What kind of memory do you have? Since you have a EP43-UD3L i recon that's DDR3 memory? In that case try and get one of these:
- Asus P5Q3
- ASUS P5E3 PRO ATX iX48 (harder to get these days and only a few reviews available (I just ordered this one)). This board is supposed to be very much clockable and is approximately 130 euro.
If you don't have DDR3 you should go with what Tecmo just posted.