We've had a http://www.johnlewis.com/panasonic-nn-st452w-microwave-oven-white/p231631742 for over a year now since our old one broke. 900W and its big (you can get a big casserole dish in it...we do stews that last us 4 days in it!). Just used John Lewis site for the picture...I'm sure you will get it cheaper somewhere.
I have a Sharp Dual Microwave/Cooker. It is 950watts. Brilliant machine, although I don't think I've ever used the cooker setting. It's large enough for the biggest casserole dish.
Yes, really, jj. Buy a new one. I was trying to repair my tumble dryer following instructions online. I kept blowing the fuses in the whole house.
When I eventually conceded defeat, the electrician told me I could have killed myself with what I was trying to do.
I don't know if he was joking or not, but just don't bother.
Bought and all. Just waiting for neighbour to come home from work to lift it in for me from the car and take the offending one out so that I can dump that.