It always comes down to the question of what software do you want to use. Then, buy the computer that can run that software. In your case, you have determined in advance that you want to use Adobe Creative Suite, which is available for Windows or Mac, so it doesn't really matter for you. If you are already familiar with PCs and Windows and that's what you already know well, then the Windows PC with the Windows version of Adobe Creative Suite would probably be better for you because you would have little or no "getting up to speed" time except with Adobe Creative Suite if you've never used their programs. The only suggestion I would have for video work would be to study what your entire system will be, from beginning to end, including all cameras, microphones, scanners, any other type of input, your computer, the interface between the camera and the computer, what software you will use to capture the video from the camera to the computer's disk, what software you will use for editing the video, what other software you will be using, including for your final output, whether that is a DVD, a web site, online video clips, whatever.
Make sure that at every step along the way each part will be compatible with the next part along the chain, so that there won't be any unexpected blockades and you won't have to make your data jump through any hoops or do any unnecessary conversions. Plan out your entire workflow and make sure everything you buy is compatible with that workflow. For example, I think the most common video standard now is probably DV, so if you buy a DV camera or miniDV camera, it probably has a IEEE1394 output. (IEEE1394 is the same standard that Sony calls iLink and Apple calls FireWire. I don't know what it is called on PCs.) If you can use a FireWire cable to plug the camera directly into a FireWire port on your computer that will make the transfer of video data far more efficient and with less or no loss of image quality. The video capture and editing software you use will have to be compatible with that same format (and it probably is, but it's good to study the specifications before buying the program). The process of video production involves moving the data through so many processes (recording with the camera, capturing to disk, editing, rendering, authoring and then encoding to the final product) that you want to make sure the process is smooth and there are no incompatibilities along the way.
The beauty of Apple's scheme for this is that all of those worries are already resolved for you before you even buy the computer, as long as you use their software. You would just have to make sure the camera you use is compatible and has a FireWire output (and most do). Apple designed their software to make it easy for a beginner to go through the whole process without having to worry about the technicalities, and the iLife software that comes with every Mac includes programs to do these and they all work with each other. You would capture and edit your video using iMovie, capture and work on still images using iPhoto, collect and organize music using iTunes, or even create your own music using GarageBand, then bring all of these together in iDVD to author, encode and burn your DVD. All the individual elements such as video from iMovie, music from iTunes and stills from iPhoto all magically show up in the menus in iDVD and you just drag them to where you want them. Apple has made it easy to get through what is actually a complex process, and you can literally produce a playable DVD within hours of taking your Mac out of the box the first day. I don't believe any version of Windows has that same out-of-the-box capability at that level.
However those are generally considered "beginner" programs, even though you certainly can produce high-quality output with them, they lack the full feature set of professional-level programs. Eventually you will probably "graduate" to professional-level programs, and then want to buy such programs as FinalCutPro or FinalCutExpress instead of iMoive, Photoshop instead of iPhoto, any number of music and sound programs instead of iTunes and GarageBand, and DVD Studio Pro instead of iDVD. Or you could buy an integrated package such as Adobe Creative Suite, which probably has just as good integration as Apple's programs have. But for someone just starting out, who doesn't really know what software they want to use, I try to steer them in the direction of buying a Mac and using the iLife suite to get their feet wet in the whole process, and easily get quality results without tearing their hair out, and then when they feel more comfortable, move on to pro-level software if they want to or have a need to.
Another reason I like the Mac environment for working with video is the community of software developers and the tradition of producing elegant, quality software that does what it says it will do and is compatible with the standards of the Mac environment. It goes back to Apple's original Human Interface Guidelines and general concepts for the computing experience. The other big plus is the online community of people working in the same area, including the discussion fora at Apple's own web site - I have found them to be helpful and knowledgeable and quick to respond to questions - and these are just other users and video professionals, not getting paid for participating in those fora. I'm referring to
http://discussions.apple.comThat's just my opinion on all of it, and you could get more opinions and advice at this web site:
http://www.videohelp.com/