Get hold of a 6230i version, rather than a 6230 - afterall, 208x208 is alot bigger than 128x128
Alternatively, the mmapi sound player is pretty robust on the 6230i.
It should do ok with any version that is targetted at any other midp2 handset with a 176x~220 screen.
A build for the Motorola Triplet family is probably your best bet, though you may also be ok with a build for a highend Samsung. (not the D500 though, to pass Java Verified - there is a tendency for builds to use the Samsung API [gets around a firmware related call interupt bug in the VM])
Other contenders are the Platform 2 Nokia Series60's, O2X4, LG81x0, NEC's.
Infact, there are dozens of builds that should work *fairly* well on the 6230i - have a look on JBenchmark for some near-compatible handsets.
I'm suprised you can't get a 6230i version tbh, its a major device - as it is on the Vodafone drop list.