Dell Latitude D830 Motherboard differences

I thought my days of dealing with Nvidea ended with my old HP fiasco (how did they survive? on the backs of their customers)

I bought this older laptop because I need the RS232 port and don't want to deal with adapters. The unit is running win7 with no other issues than occasionally the screen blacks out with a driver problem stated- drivers are all updated with latest bios. My next step is to replace the motherboard with a Intel GPU motherboard and have noticed some physical differences and A00-A02 versions, other than the heatsink is there something I should be concerned with? Other than fleabay- is there some preferred venders that you have had good service with?