Best Core 2 Duo setup?

[zipeee]

I am thinking of getting a core 2 duo chip, and wanted opinions on:

 

1. Best / most compatible motherboard for OS X 10.4.6/7 on Core 2 duo?

 

2. Should I go with ATI X1600-1900ish, or consider Nvidia as well. Personally, I like Nvidia better on the Windows platform, but is it running well enough on OS X with the macvidia drivers these days? Currently on my older AMD X2 system, I am using an X600 working with callisto drivers. (runs ok.).

 

Thanks

Z