Can't Decide the Mobo: Asus vs Gigabyte!

These are all fine boards. I would make sure each has the features I want and then buy the one that is the least expensive.

If no crossfire and no overclocking: DS3L and ddr2 800 ram instead of 1066

Why 800Mhz instead of 1066??

And one more thing;

DS3L is supporting DDR2 but DS3R is supporting DDR2 and DDR3 that is an advantage?

Why 800 instead of 1066? It was just a suggestion,it really should depend what you want/need

1066s are basically good quality 800s that will overclock to 1066. Yep, and you have to do it yourself as the mobo will set them up as 800s(as thats what they really are). Also the difference in performance will not even be noticable, unless you run some specific memory benchmarks. In everyday use you wont see any difference.

So:

If you dont care about that and the price premium(around 20% where i live) on them than go with those reapers.
Especially if somewhere in the back of your mind you do consider some CPU overclocking at a point in future(and most people end up doing it anyway  

If you do care - go with CL5 800s, they will do just as fine

As for ddr3 on that platform - forget it, theres no advantage at all. Plus that mobo only has 2 slots for ddr3 so i dont see a point. And personally i stay away from all "hybrid" solutions. Go with ds3l or ud3l.