No you arnt going to replace a canister with a HOB.
Reason people can replace a SUMP with a canister is ROOM. Largest HOB you will find is like 3 gals. Most sumps are around 50% the water volume for the tank.
Now you can certainly ADD a HOB refugium...and I am sure it would help. but it wont replace.
If you look as some of the larger hob refugiums. They will fit aand are designed to a small skimmer like a tunze 9001. That is also the same size as the tunze comline mechanical filter.
I'm looking at doing the same. I haven't been impressed with any of the small skimmers any way and I hate the can on the floor. The comline series is designed to go in tank too. Ther at two tunzee filters one with a standard pump and one with a large powerhead. Both appear to be rated up to 100 gal. I found recently them on Amazon and the specs are on the slightly hard to search tunze website.