I use fluval and aquamanta, both canisters and very good. Never used aquatop but I personally dont like filters to have uv
built in due to malfunctions and also you should check that you can freely turn the uv
on and off at will - if you were to treat for disease etc you may not be able to add treatment whilst uv
Personally I would choose fluval out of the two options, I know the aquatop seems better value but have you asked yourself why??? Im from the uk and also never even heard of aquatop - fluval in an internationally recognised brand. Your choice dude but filters are really important to get right!