wohhhh thats like every thing not just aquascaping?
Do you have and preferences?
Heaters I've been interested in cobalt neo-threms lately and viaaqua and Fluvals E heaters.
Also liked Cobalts EXT canister filter, for a 55 I would probably use 2 Fluval C3 or C4 HOB
's or 1+ the EXT, just my opinion ATM.
For my 150 gallon used 160lbs of eco complete and 50lbs of some rock and dumped it in all haphazardly, figured id let the randomness do my aquascaping for me. For a 55 you could do 4-5 bags of eco complete or 2-3 and some rock.
Do you want for light, LED
or T5's? What plants will you have?