These are what I like to call "modern problems".
I wish I could help with the HD/SSD issue but ,to be honest, I'm still on the fence with SSDs. Hard drives are still good and are still dependable. That's normally good enough for me which is why I still haven't played around with SSDs.
The one big benefit with an SSD is faster access and load times, which might point to that drive as a good candidate for games.
The only thing which has kept me off the SSD bandwagon so far is data stability and read/write/rewrite cycles. As I understand it, there are a finite number of times an SSD can rewrite a sector. This finite number may be massive, but its still there. Mainly, I want to give SSDs a little more time to see if they have long term (5+ years) stability.
I've already PM'd you with my views about Steam and GOG. They have advantages but they also have some headaches. I'll leave it to the rest of the crew to chime in, since I don't use them.
In terms of sub games, check around the forums, here, for what's out there. Then head over to YouTube and enter the game's name in the search function. You can find many hours of play-throughs to give you an idea of the game's graphics and play-abilty. Its like a free demo before you decide to buy.