Hi i have a 90L reef (i think you have see the pic before)
Having a Canister Filters (Fluval204) means you would want to put things like bio ring or substrat in it which is for biofiltering. They do a good job of filtering but will build up N03 which is bad for corals. (If you are running a FOT then is fine)
It terms of using LR as filter is to keep NO3 as low as possible. In todays reef keeping the best and easy way would be lots LR + big skimmers.
But keep in mine that only using LR as filter in a small tank would mean u can only keep a few small fish.
I personally do use a Canister Filters with substrat in it for bio-filter due to the reason that i like to have more fish in a small reef tank. I just do more water changes to lower NO3. (Currently have 6 in it) Also have marco algae too.
So if your ideal tank is a classic Nemo tank with a few coral, LR and skimmer would do you. If you are like me wanting to add more fish in later on get a canister filter but don't go for fluval, just get a 1200L/h Atman or Jebo (new version) would be ok. If you got the money go for eheim 2227 wet/dry. Best canister around and also can acts as a wavemaker in a small tank.
Anyway no matter what a marine tank must have a skimmer, very important. Go get a cheap one if you a short of cash. But i advise you not to go for one with a air stone, one with pump won't cost much more. ViaAqua and weipro both make a hang on one for about $150
Surface skimmer just get one when you water surface is oily not something you must have to start with. Remember don't go for the one with plastic fitting and float around...really crap i had one too. Go for the Atman one should be much better.
God~~what am i doing~~ i type a page.....