Hey there, for your intents and purposes, the 2.0 quad core with 256mb gddr5 should be more than enough to handle CS5 and any other graphics programs like that. Yes, upgrade to 8gb of ram if you are going to be dealing with very large sets of photos at once. I personally only got the 4gb with the 2.2ghz simply because I know I will have no need for such extensive memory resources, and have had no problems so far having over 20 hi-res photos with multiple layers on CS5 open at once. The jump from 256mb graphics to 1gb is noticable, only because I am a gamer as well, and I can easily run Starcraft II on extreme settings with ease. My fps stays at 60 no matter what, due to the awesome power of the new i7s. However, if you have no intents of running high-demand programs like that, I don't recommend you spend the extra $400 just for more video memory and .2ghz more processing power. The 2.2 quad core turbo goes up to 3.3ghz max, and the 2.0 goes to 2.8, I believe. As for a solid state drive, if you are dealing with photos regularly, you will see a significant load time increase, if you are comparing it to a base-line 5400rpm drive. Honestly, the load time for a couple hundred MB of information between a 7200rpm HDD and a SSD is only a couple of seconds, whereas if you are loading several GB of information of video or anything with a lot of memory will you see the true time difference. I recommend a 7200rpm HDD simply because it will still do the job excellently and is much cheaper. But if you have the money, then why not, right?
Hope that helped. I've only had my 2.2ghz for a couple days now, but I absolutely love it, and it is lightning fast. I haven't even tried to daisy chain with the thunderbolt port, but I assume it will amaze me as well. Cheers!