DQ4 DS's cut content is only in comparison to the Japanese version, and it's really not a huge deal some people make it out to be. Should party chat have been localized? Sure. Does the lack make the game horrible? No. It's not like there was party chat in the NES version, so unless you keep up on imports and such, you wouldn't even know there was anything cut.

Some people also complain about all the accents used by the various towns, but personally I love them them and think it really adds a nice atmosphere to the game. When you get to a new area, you really think you've journeyed someplace different rather than down the block.

I would say start with DQ8 on the PS2, though. It's not just the best looking DQ, it's one of the best looking PS2 games around; it's like a cartoon come to life. Gives you a chance to try out the gameplay without feeling like you're playing something from the dark ages (not that there's anything wrong with that).