wow man.. there are tons of costum roms out there!
some of them are AWESOME!
i give you 2 that i have tried and i can guarantee you they are fine:
1. u8800-oxygen - Browse Files at SourceForge.net
this is a oxygen 2.3.2 costum ROM. It runs android 2.3.7 and it is super fast, stable, and battery last for like 2 or 3 days!
here is a video i've made of this ROM:
Ideos x5 Gingerbread 2.3.7 Oxygen - YouTube
This is a MUIU based cernel ROM that also runs on android 2.3.7 also stable, fast and battery lasts longer than official ROM.... Youtube link:
Ideos x5 MIUI v2.1.20 android 2 3 7 - YouTube