Diesel more durable (but may be heavier)Depending on the HP of the mixer,I'd go for no less than 1,8kw,2.5 if you can run to it.Useful to have 220/110 volt options,possibly also a 12DC output for battery charging.No first hand experience,but Wolf regularly advertise and sound value for money
http://www.wolf.tv/view.asp?id=145§ion=Gen erators&gclid=CIimu8-qlpkCFdQB4wodQS0Vbg



