It is always better to overfilter. Get the biggest you can afford. Fluvals are cheaper and Eheims are also available and everyone has their own favorite. Generally canisters are better than HOBs but HOBs are very inexpensive and two nice ones are less expensive than one canister. I have used all of them but they are all OK as long as you listen to what the Forum Guru's say (about inserts) rather than paying attention to what is put out by the Manufacturers who are just trying to increase profits.
I use Rena Filstar XP3 or Aquaclear 110 on 45 gallon tanks. Manufacturers claim they will work for 100+ gallon tanks. I do not believe that would work for my tanks.
With either canisters or the Aquaclear aim for at the bare minimum of 5x your tank volume per hour, though I have found closer to 10x is better.
With cartridge style HOB (Hang on back) figure at least 10x. (and don't get them anyway- they are not worth the savings. Cheap junk)