From the sounds of it the poster may be best of getting hold of a 320MB 8800 GTS for cheap as they are proven to get really good results in 3d max. With regards his system I would put the following recomendations in:
1. Intel Core 2 Quad Q9550 2.83Ghz Processor - I wouldn't overclock a rendering system due to the intense nature of the usage. The newer Quads are more efficient at the same speed and this is a faster chip. As such it could easily shave about 20% of your redering time compared with the Q6600.
2. Consider cheaper motherboards - Any well cooled Intel based motherboard G35 upwards will be fine. Again the most important thing is a stable/quality board rather than one with the ultimate features.
3. Run your two hard disks in RAID-0 - Hard disk speed has little performance affect in rendering systems. Your data takes a great deal of time and effort to creat so make sure it is backed up.
4. Get the extra RAM - RAM on the other hand definitely affects performance.
5. Invest in some good quality quiet cooling - Install maximum fans in your antec case, but run them at a slow speed, get a better cooler for the CPU too. Your system will be on and hot for long periods. It will also probably be on overnight in the same room as you. Make it cool and quiet.
