I have the honwave 3.8 ie , and it will take a 25hp.
The £1200 you mention would buy you a new honwave.
Don't be put off with all the bombard is best talk, there are other boats out there which are far more capable than people give them credit for.
If you want the roll up/fold up capability but small rib performance, look at the foldable rib from foldablerib.com.
Talk to the guys on f-ribs and sibs, as a few of them have upgraded their bombards and honwave to the f-rib.
There's also a review here on the honwave. http://bit.ly/1MrBcsJ