Like the other people said, go with a Fluval 304 or 305, that is more than adequate by itself for a 55gal, you can however spend a bit extra and go overkill with a 404 or 405. If you're in Europe, Eheim and Sera canisters are good choices too, but Eheim is expensive outside of Europe and Sera products ussually aren't readily available outside of Europe and Australia/NZ. It's worth spending the money on a good quality, name brand canister filter, you'll get a decent warranty (3 years with Hagen-Fluval) and wont have problems getting parts if something wears out or gets broken.
Don't worry about Hang On Back filters on top of that, it's not necessary.
Definently go for a glass tank, acrylics are nice when new but they scratch easily and after a few of years of scratches build up they ussually look pretty bad.