SSD and OS?



After a few years of Windows patching, you're Windows foot print could grow to 40 GB in size. 128 minimal, 256 at least. I have 240 GB and it's mostly full, considering BF4 is like 30 GB alone.
 
You can install win 7 64 on a 32GB SSD (especially if you follow some tips/tweaks to reduce the installatin size once in windows)... but as others have said I would go for a 60/64GB SSD.

Typically the smaller sized SSD's in a family perform MUCH slower than the larger ones as a 32gb will only have 2 memory "chips" which can each move 25MB/s - while the 128gb version uses 8 "chips" and has 4x the maximum sustained transfer speeds.
 


You'd be better off getting one larger one, look at some reviews of various sized SSD's in the same line/family, one 256GB typically is faster than 2 smaller ones and that way you never have to worry about "wasted" space on the OS drive that you could really use for games.

That said - I prefer to leave games on a mechanical drive - main benefit of the SSD on games is at loading screens, and unless playing something that having faster loads give you an advantage the additional 2/5/10s to load isn't a big deal to me.
 
You may think now that the boot drive will only be for the OS but you will find that there are certain "core" programs you'll want on it. At least that's what I and most others have found. Personally, I use an external HDD for bulk storage. I prefer external because I can shut it off when not in use.
 
32gb is enough, just barely. But, you will need to be very vigilant in cleaning out space. Not worth it.
How barely also depends on windows version.
Regardless, I think 32gb is just too small. 64gb is bare minimum, and 120gb is really better.
Larger SSD's will perform better and last longer.