Personally I wouldn't mix. I would look into the latencies of the DIMMS and running voltages, if they are different I would recommend selling the 2 random DIMMs and buy the same model/make as the ones you have already got.I only have 2 of the same Brand Ram, the other 2x512mb Sticks are Random Brands.
Personally I wouldn't mix. I would look into the latencies of the DIMMS and running voltages, if they are different I would recommend selling the 2 random DIMMs and buy the same model/make as the ones you have already got.