I've got 2, an older Avon airdeck 2.8 SIB and a Zodiac active 5, 3.8M airdeck, I've got a 2.2hp ultra lightweight mercury 2 stroke engine which will power either of them, but not on the plane, and I've got a Yamaha 8HP 2 stroke outboard that is ok on the zodiac but will only slowly plane with 1 person in, 2+ and it doesnt get near planing speeds, but with the 8hp on the lightweight Avon, its very fast and a bit skittish.
The Honwave T32 is a brilliant allround choice, but I'd pair it up with a Suzuki 15hp direct injection 4 stroke engine, the 10 is the same weight as the 15 anyway, so you might as well have the little bit more power to play with, handy when punching a tide when loaded as you'll get less spray coming over the sides when on the plane in any sort of chop
The Honwave T32 paired with the Suzuki 15hp direct injection 4 stroke would be my ideal choice if I was doing it all again and would be as happy on the rivers ticking over at 5 knots as it would be doing 20 knots at sea !
I'm not sure about registration or insurance or anything as i use mine at sea in Weymouth and its covered under my bigger boats insurance, but I believe there is a river license you might need depending on the river you will be using it on
