Should I use a Canister or Wet Dry system?

Hello people... I've been thinking of starting a saltwater aquarium. I've grown a little tired of my freshwater tank. The colors that the saltwater fish have are just awesome. I have a 135 gallon tank with 2 Rena XP3 canister filters. I also have 2 Marineland Maxi-Jet 1200 power heads that converts to a circulation fan/ pump mode. A guy at a local pet store said that I can use the items that I have with no problem. Is this true? I don't mind the maintenance. I don't want to give the canister up if I don't have to. I've looked online and it also said that I would be fine. However, some are going away from this idea of the 2 canister and 2 power heads. Will it be safe to use the canisters instead of the wet dry system/ sump? Thanks for your time.