VERY newbie question !!

I am just about to order a new system and need a bit of advice. The system I plan on building uses a gigabyte ga-7vrxp board with a 2100 xp proc. I am definitelt intending to clock the thing to the max (yes I am just beginning but I want to push it as much as possible) I am an avid home machinist and engineer and I am considering a freon immersion case to hold the board/cards with sealed connectors for the drives/usb/ser/par etc so when i really push it wont be likely that heat will be an issue, however my question stems from what is probably a fundamental misunderstanding of pc architecture: I am considering which ram to get for this machine and I am wondering should I get 2700 ddr or is there a POTENTIAL performance advantage to getting say 3000 ram (at the same cas latency). would the higher freq of the 3000 allow for higher memory bus frequncies or is there a compatability issue. I know there are probably better overclock boards such as abit's but I need the parallel port/serial ports

Thanks in advance for any help

The main thing is to get Quality Name Brand RAM. If you're going to cool the way you say PC2700 should be adequate, but 3000 might be better, just watch and make sure the 3000 is not just an OC'd 2700. Post some benches when you get it built, sounds like it will be fast. Quite the project you're undertaking.