noob to laptops!

I am going to be buying a laptop in the next week or so and I have font two that I like. There are a few things that im not clear on.

1) CPU - AMD Turion64 X2 TL-50(1.6GHz) or Intel® Core™ Duo Proc T2050 (1.60GHz/533MHz/2 X 1MB L2 Cache) Both are DDR2 533. Dont know which one will give beter performance?

2) Both have shared video memory. Now with the shared memory will I see more performance out of the video card if I upgrade the ram to DDR 667? more bandwith? Both laptops come with 512 of memory so im going to upgrade that right away and dont know if I should get DDR 533 or DDR 667! I will put in a Dual Channel kit so the memory will match.