well you have live rock (assuming this is for your 10g tank). Why get other filters? Live rock is a natural filter. Canisters and other types of filters (skimmers are not a "filter" ...well i guess in a way they are since they pull stuff out, but having one certainly isnt causing any problems) will only make it worse if its a reef, which i'm assuming it is since you've got reef lighting. They will make nitrates very fast and will start killing/stressing stuff out. dont get a canister.
And now, what skimmer are you running? Is the remora in your sig the one you've got? And if so, why are you unhappy with it? How deep is the pump, have you cleaned it recently, and what pump is it?
i've got 3 tanks currently set up. I've got a 3g pico that i set up and take care of for someone else, i've got a 29g reef, and my 40 breeder reef.
On the 3g pico, all i use is live rock and flow from a HOB filter (which i only use for flow and carbon, no other media). It is a reef and even has a couple sps, which are absolutely taking off since placing them in there after doing not so good in another tank of mine.
the 29g tank is actually being taken down now (slowly) and all will be going into a 16g bowfront. But right now there is a remora skimmer on the 29 and it is awsome. The remora was on my 0ld 55 and it did great on that too. And i never adjusted it or anything, just threw it on. So i'm thinking you may have just not set it up right or something if its not working on a 10g tank. But also in the 29, i've just got about 25lbs of live rock and lots of flow.
In my 40 breeder, i've got about 50 or so pounds of live rock, about a hundred pounds of live sand, and lots and lots of flow. Thats it. No canisters or even a skimmer (cuz the skimmer didnt work and i got no money to replace it

). But this tank is doing the best surprisingly, considering there's no skimmer. The remora will either go on the 40 or the 16 once the 29 is completely down. Probably the 40 since it will have sps as soon as i upgrade lights. I will also have sps in my 16, but its less water volume (so one isnt really needed as much) and plus i'm gonna experiment with a lot of natural types of filtration (will have several clams, and in the sump i'm gonna have a xenia forest since that is a natural filter).
And for maintenance i really dont do a whole lot. I top off very often, but thats the main bit of "maintenance" i do. Other than that i do about 1 small water change per month, but i'll be doing more when i get sps corals. My softies tend to do better when i dont do as many water changes. I've gone 2 months w/out one before and they still do great.
Sorry for the book, but i just dont think that you should get rid of the remora. I've run mine on 3 different tanks now and its had the same result on all of them. Amazing.
And i REALLY dont think you should get a canister or anything other than lots of flow and live rock.You got enough rock, just make sure you've got enough flow and not too big of a bioload.