I just ordered the Realforce 87u 55g from EK. From what i've read is that the 55g is pretty strong at first but once you break it in it will feel like a 45g that isn't broken in. I heard that 45g topre once broken in it feels mushy (which might be better if you prefer lighter switches).
If you prefer blues over browns I would say get the 55g
If you prefer browns/reds over blues I would say get the 45g.
If you cannot afford a topre I would say my switch I would get would be the cherry mx clears because they are similar to browns but with more of a tactile bump. Keep an eye out for WASD v2 with clears and the FC660M (from qtan, a vender here @ keyboardwow.com) is where you can buy the leopold mx clears.
Do some google searches:
http://lmgtfy.com/?q=45g+vs+55g+topreI heard that reds are good for gaming but not so much typing, browns and blues are in between I would say and from what I've heard are good overall aswell.
I would stay away completely from variable, people say that 30g is really too light if you were to rest your pinkys you might be holding a key down.
You'll get more feedback from 55g but most likely smoother with 45g.