Why not just buy (or club together with a couple of other hourbuilders and buy) a cheap PFA single-seater and hourbuild in that?
August's PFA classifieds shows either a new Evans VP1 or a lowish hours Rans S5 for £3,500; let's say 2 of you buy it, park it at a friendly farmstrip (I can show you one that'd have it for £30/month + £50pa membership), put 100 hours on it each over the year, then sell it for £2000 (which would be a bargain for somebody so you'd get rid of it quickly), add in about £250 insurance, fuel about £15/hr, another £5/hr to cover odds and ends and...
I reckon you'd get your 100 hours of hourbuilding £41/hr which would go down to £31/hr once you'd sold the aeroplane to the next hourbuilder.
G