How BIG of a Generator?

Now, I have to locate a propane generator that will suit my needs.  I want to stick to propane, since I have everything running off propane.  I will only be running a standard home refrigerator/freezer combo, a sandwich prep refrigerator, and a bun toaster.  Aside from interior lighting, thats all the electrical I will be running.  I will be using the generator full time as I will be a wandering food truck.  All my cooking/water heater equipment is propane.  I just dont know how big I should go with a generator.  Generator noise is another issue I wish to address.  Any help is appreciated.  My budget for a generator is @ $1000.00 and I have seen a few that meet that budget.  I just want to avoid any mistakes, as I am very new to the food truck industry.  Tips and suggestions is always welcomed.  I am doing this build by myself, and rely heavily on this discussion board for information.

Refrigerators don't use a lot of power when running, but depending on type, may need 3 times the running wattage on start up, when compressor kicks in. Toasters also use a pretty significant amount of wattage. You need to find specific maximum draw of all items you will run at same time. A big home fridge may need 2000W on start, smaller cooler, 1000-1500 on start, and toaster 1500 or more depending on size. 

Watts = Volts x Amps
Volts = Watts / Amps
Amps - Watts / Volts

ok, thanks.  Any of you have any experience/comments about a DuroPower propane generator?  I am looking at a 7500W model for @$1200.00 new.  They call it a the 7500W Silent Propane Generator.  Looks like it would be alot quieter since its all enclosed.  Sad thing is its presently out of stock at all the places I have looked online. 

finding a propane generator is a good idea as far as durability goes. Less carbon build up and less cost for oil changes. you will find that you can double the life of the engine with the use of propane. Also if you use synthetic oil you can put a hour clock on it and go to 100 to 150 hrs on before oil change. Mike

Size the gen-set to 70% of its max output.    You don't want the motor running wide open all the time.   This will give some room for startup of surge motors.     ..... Spinning motors (frig & ac compressors ... ect) has a power surge when starting. The surge varies, but the rule of thumb its to add 25% to its running load.
Add up all your power equipment to get total amps required.   ... Assuming the main breaker of your service panel is not grossly over size, the gen-set power output should be equal or more.