FF6 is a great game to get as well as FF7
I recommend getting both of them if possible
As for how well they will look on the PSone's LCD screen I can't honestly say since I haven't got one, but I wouldn't thought it would effect the game in anyway myself
EDIT: Btw welcome to the forums, its nice to have new members here
I'm Soul Angel
Have fun here and post lots!
And don't be afraid to ask for help because we are all nice and friendly people other here