Erm.... these are the worst consoles you could have for JRPGs.... And no gamecube controller....
Well, there are some Disgaea games and Tales of Tempest for the DS, but I haven't played them. The Mario & Luigi games are a definite recommendation, but they're not true JRPG are they..?
Either buy a Gamecube controller (really, how much could it cost?) and play Tales of Symphonia wich is a great game, or buy a PS2, wich has a huge JRPG library. You need a PS2 to play SMT 3: Nocturne anyway, wich is an absolutely amazing JRPG wich you must play if you call yourself a JRPG fan (Persona's got nothing on Nocturne by the way).
Oh and whatever you do, don't get the Sypmhonia spinoff (dawn of the new world), it's horrid (Courage is the magic that turns dreams into reality, lol).