Your hardware is in directtion
WORST CASE hardware for
easy OSX86 usage !!!
GPU = problem (no support, no QE/CI = unusable )!!!
CPU = problem (only patched kernels may run) - only AMD cpus may give more problems

8 GB RAM may give major problems with IDE HD/DVD usage / IOATA drivers need to be patched.
you can try kernel flags
-x -v -arch=i386 cpus=1 maxmem=2048
to get at least an verbose text to show whats the problem
I would think about an switch to an newer (used) mainboard (gigabyte or other recommended) with C2D CPU (or at leadt an Core Pentium CPU ) and an gpu which is supported by OS X (cheap : NV 6600 GT, NV 8800GT).
SL with ATI is also todays a bit more tricky than using NV cards.