If you buy a PS3 you have access to every FF (including Tactics) except III. Not only that, but you can get them in 1080p on an HDTV with Sony's update. Although the only game that suffers from Sony is FFVI, the load times were just too much.

Another great choice is the Nintendo DS as you can play 1-6 on it (including Tactics Advance and soon Revenant Wings and Tactics Advanced 2). I hear the remake of VI is really great, but that's the only thing Nintendo has over Sony.

Another good bet would be the gamecube and a gamecube GBA player since you could play 1-6 (minus 3) on a TV, which the remakes look really great on.

so yeah, a ps3 would be your best bet, but if you're trying to play VI and III a DS would be good, or you could just get a used GBA SP, which are real cheap now, to play VI and a translated rom for III, which is, of course III.

Also, I would have to say beating all of the FF's is much closer or less than 500 hours than 1000 since you can get everything and complete the first 6 games in 35 hours or less (less than 20 for I, II, and IV), although IIIDS seems to be a little longer for some reason.