yeah both are fine -- i have a 60 and went w/ an eheim wet wry 2229 and a rena filstar xp3 also. I'm not rich, i just searched and waited till i found good deals-got a new rena for $70 and the eheim was $120 new. anyway, I love the wet dry because it has constant water output but then as the canister empties it shoots a strong stream of water --creates a wave effect and in your 55 the water level will raise and lower about 1-2 inches --looks like high tide and low tide. I threw in the customflo starter kit so you can direct the spray anywhere. the rena is really powerful too - honestly the tank could run on either by itself though.
the water movement, live rock, and either eheim would work fine