haha get a YZ if you can if your mate has an RM and you want to be a little different, although if a nice RM comes at a good price grab it, imo the rm is a better bike, handles awesome and still has some good power, 01 models lack a bit of bottom end but that can be fixed with a pipe, i was recently in a similar situation as you but have a lot of mates with bike's and could or had ridden them, as far as 01-03 model jap bikes i found (best for me) 1: RM250 2:YZ250 3 CR250 4 well don't really like the feel of the KX but its not a bad bike either, mate had an 01 with pipe and reeds and was still low on power.
i ended up getting an rm cos i love the skinny feel and the handling, feels like a 125, and with a few mods its got more power than you need. you will find that when you start riding and meeting other people there is no such thing as different, people have all diff brands of bikes, so in that situation i would reconmend the RM