Re:using inverters versus gensets
Think about all the appliances you may run, you've got to have more than just this one...lights, signs, cash register, fridge/freezer, radio.... Amps=watts/voltage
Add up all their amp ratings and multiply that by the number of hours per day you think you'll be using them. That gives you the number of amp-hours your battery (probably multiple batteries) needs to be able to supply. Add some wiggle room to be safe. Size your inverter to supply full load plus wiggle watts=amps*voltage.
Charge time is a consideration. If you drain your batteries during the day, they've got to charge back up and that usually takes longer than draining them.
You'll definitely be into alot more money for this system vs a genset. You could probably get by with a relatively quiet inverter generator. Smaller solar panel/inverter/charger/battery systems can supplement your generator and you can upgrade to gen-free later.
Keep searching the forum, there's a lot of good discussion and a number of good links. Swing by an rv parts seller and see if they'll give you a catalog to browse. Develop your understanding of how this stuff works and you'll avoid paying too much for a package of components you could have gathered yourself.