We hired a Silent running 1.4Kw 4 stroke honda genny (about £700 to buy) last year from Rapid hire in Wokingham, about £40 then for a week, a worth while option if this is the only time you use a genny, plenty of grunt (make sure its covered by you house insurance), Costco have some good deals on .8kw 2 strokes, similar prices to B&Q but with their no quibble garentee (return it at any age with the receipt and keep up your membership and they will refund or credit to recipt value).