For chopped worm I'd use the dendroneba variety as they're cheaper than lobs (assuming you don't have your own worm farm).
Use longer sections as hook bait (or lob sections) pushing the point of the hook down into the cut end then out through the skin. This helps hide the hook shank inside the worm and ensures the point isn't masked.
You can bulk out the chopped worm groundbait with brown crumb or similar, even add some Van der Eynde liquid worm to juice it up a bit. Tasty!
Personally I'm just learning about float fishing so can't advise any float set ups but I've caught plenty of Perch, Roach Bream etc... on simple running ledger rigs with worm bait. Oh and of coarse eels.
