Root Rooted, what's next?

I've just managed to root my SGS, but I really would like flash custom kernel to get the voodoo sound and maybe if there is one that makes phone even faster, it would also be cool. I've found this list of custom kernels:
Download/Flash Galaxy S/SGS Custom Kernels
But it says in every one of them that firmware 2.3.4 is highly recommended, but mine is only 2.3.3. What should I do? These might be nooby questions, but any help would be appreciated.

The Phone specs:
Model number: GT-I9000
Firmware version: 2.3.3
Baseband version: I9000XXJVO
Kernel version: se.infra@SEP-51 #2