Here is a link to some pure sine wave inverters and the who's and whats of what in the heck that means.
http://www.nooutage.com/inverter1.htm Basically an inverter changes direct current to alternate current. The process by which it accomplishes the task determines which babies like the formula and which ones don't. A quick search revealed that some honda generators put out pure sine wave ac. (the stuff computers and amplifiers like)
Oh one other piece of equipment that might help is called kill-a-watt. you plug your gear into it and then play for a couple of minutes or half an hour as it's only got the one 3 prong outlet, and it will tell you what you are drawing in peaks and constant power. You may have to do different parts of your set up identically over and over until you have everything that runs tallied up, but at least this way you will know really how much juice you need when you start calling about genny rentals.
last I looked the killawatt thingy was 20 bucks
here is a better explanation page
http://www.sinetech.co.za/invselect.htm took me a while to find one.
