Nether ores is good if you turn down some of the spawn rates. When I played tekkit, I could get two stacks of diamonds in half an hour, just by strip mining in the lower levels of the nether, under the lava.
Minefactory kinda unbalances the agriculture stuff, but the animal breeding, sorting and harvesting blocks are really nice.
I am a little worried about modular powersuits, because it really messes with the IC2, gravisuite and Gregtech balance, since it is a whole lot cheaper than the quantum and gravichest armor, and provides similar armor benefits, and some of the extra features. Kinda defeats the purpose of the drills and chainsaw too.
Im not familiar with XReliquary, but apparently it adds transmutation, and could be pretty unbalanced. If you dont want transmutation on your server, I would recommend disabling it or those items.
But definitely upgrade your server, sounds like a great value.