What I have been told is that you need to use the minefactory one becuase it needs a lot more to run it and also it Costs a lot more to make it so it makes you have to work for it
Yes, block RP2 block breakers are uncraftable. Since RP2 and Minefactory Reloaded both provide block breakers, the admins have chosen to use only the MFR one as it is more expensive to craft and requires a power source to operate. However, the RP2 mod is very messed up right now and many of the block IDs have been altered. This is probably what is causing your game to crash. I've had my game crash when trying to craft block breakers, filters, transposers, and a bunch of other RP2 machines. This should be fixed in one of the next server updates. I think its got something to do with compatibility with MCForge or something like that. Anyway it should be fixed soon.
Also, Levint, can't wait for the new processor. Sounds awesome! Should do a lot for helping lag issues and such.