I have a Asus P5K still and I OCed my E6550 to 3.5Ghz no problem and got 3.9GHz with my E8400 on that board,
going to OC my E2140 next on that board once I get a HSF for it.
Both boards are good I think, never had a GA-P35-DS3L. But a lot of people here say there great.
flip a coin and pick that way..