Difference between these 2 GigaByte MB

[bobbyz]

I was looking at GA-M16P-S3 MB for 3800+ system

GIGABYTE GA-M61P-S3 Socket AM2 NVIDIA GeForce 6100 ATX

but local Frys has

GIGABYTE GA-M55plus-S3G Socket AM2 NVIDIA GeForce 6100 ATX

for same price.

Which one would be better option.

Another one i just saw is

GIGABYTE GA-M55SLI-S4 Socket AM2 NVIDIA nForce4 SLI ATX

Which has 2 IDE connectors. Any help is much appreciated.

Thanks.