i think most (if not all) the users who bought runcore ssds say they're WAAAAY faster than the STEC that comes with the mini. so i'd suggest you buy the 512ram and 4g ssd
and then upgrade both. and since matt (the guy from mydigitaldiscount) says that there's a shipment of 32g runcores coming in next week, it would seem the iron's hot.
but if the ssd
's speed isnt an issue for you, then the stec should work just fine.
-- edit --
oh yeah, as for the ntfs or fat32 question. fat32 has a 4g cap on file sizes..so if you wanted to transfer an iso or whatever file onto your ssd
which is over 4g, then you've got a problem. and i've also heard (cant verify) that ntfs is supposedly faster? i dunno..but that's just what i've heard..