I bought a Talamex Maxi cover for my 6.2 RIB this year to replace my second large Ducksback cover which I found lost it's waterproofness after 11/2 years. even though I sprayed it with Fabsil I still wasn't as impressed as the first cover I had which was identical to the Ducksback but bought from Bembridge Boats and Outboards.
I'm very happy with the quality of it, a very strong elasticated outside seam. So good in fact you don't really need any bungees to hold it on. It's hasn't got straps however but comes with a length of rope that you can cut to length. It's worth noting however that the smaller sizes are made from a different material than the larger ones, but I'm pleasantly surprised by mine.
Talamex 'Covi' Boat Cover L- XXL from £69.24 - Torquay Chandlers
Torquay Chandlers are very pleasant people to do business with should you choose this route.