We would like to go to Alaska for a month or two. We have been two other times
and flew into Anchorage, rented a car, and rented places to stay. LOVED IT.
We want to come back and rent an RV. Any ideas?

Do it!

Not sure what else you are looking for.

An RV "for a month or two?" Bring plenty of money. What would you do with two months?

We rented from Great Alaskan Holdays. You might want to consider their 'Spring Adventure Package' which involves driving a new RV from Iowa to Anchorage. My wife and I did it 5 years ago. I have a trip report here pn Fodor's. Click on my name and you can find it.

My friend was having the same issue. He also wanted to rent a motor-home fifth wheel for his trip. I think he purchased an rv with the help from an rv shipping company- http://www.wewilltransportit.com/rv-shipping, which then also shipped his rv back to the source. I think you should go for such an idea.

On a recent trip to Alaska I met a couple in their late 70s who had spent several weeks in Alaska having driven their RV there from Pittsburgh, PA.

I have never traveled in an RV, but Alaska strikes me as the ideal place to do so.

HTtY

What month(s)? Which parts of the state do you want to spend the most time in?
We did see quite a few people in rented RV's on our recent trip to Alaska. I'm guessing that between rental fees, campground fees and gas they were paying well over $100/day.
Gas is not very cheap in Alaska. The best deal I found was at the Costco in Anchorage. I did have to put my Costco member card in first before my debit card.

Traveling this month (July 2016) we paid $2.43 for gas in Anchorage, $2.75 in Homer, and $3.38 in Denali.

HTtY

OP seems to be one and done on this thread.