Sam,
I sure hope you'll keep us informed of your experiences once you pick up and use this boat. I'm looking forward to hearing about it.
This August, I'll be picking up a Gemini Dive 470, which is basically a 4.7m version of the surf with larger diameter main tubes (60 cm) and highjackers. I can hardly wait. I had ordered it almost a year ago, production has taken longer than normal because i specified 1670 dtx hypalon.
I had test drove a double skinned PVC version last summer (the dealer did not have a 4.2m surf at the time) and was blown away by the performance and construction quality of the craft. One thing you can see from the picture that you posted, Sam, is the thickness of that transom is far more beefy than that of any other brand of SIB I've seen.
The dealer did not have a 4.2m surf on hand at the time I was there, but told me that it performs more similarly to a zapacat than the 4.7m version. I was very tempted to go with the 4.2m surf since it is lighter and apparently a fair bit faster. Ultimately, I opted for the 4.7m since the extra capacitly would could be very handy for my applications, and I really don't needed to run zapcat racing speeds on the reef strewn rivers and lakes around here. Very fast (which the 4.7m should still provide), is good, but insanely fast like a zapcat, for me, is unnecessary (yet still good

).
Also coincidentally, last week I happened across a fellow who was selling a lightly used 40hp Yamaha short shaft 2 stroke (early 90s, I believe) for dirt cheap ($ 1400 CDN which I believe is about 650-700 British pounds). I had just picked it up yesterday and looks almost identical to the motors that Tims Osprey posted links to above. I am planning to run it later today on my 4.2 meter Zodiac Grand Raid SIB. Will let you know how that goes.
Ed the Duck,
I'm glad you saw this thread as well. You were extremely helpful to me last year in providing sage advice in selecting the particulars on my boat order. I was curious about that neoprene engine cover of yours that you had mentioned in this thread;
Neoprene Engine Cover
Do you find that it provides an appreciable sound dampening effect?