Hi all. Looking at getting 4 more GB or RAM for my iMac. 4 just isn't cutting it on this beast. TS3 plays pretty dang laggy. Can I combine the stock memory with OWC memory? I know that in the PC world, when I was building my former PC, everyone suggested running the same brand of memory. Also, should I go with one stick or two? Both options cost about the same at OWC.