As others have said, yes, FW's do have generators, but you do have to account for their weight and the fuel to keep them running. We thought of adding a generator to our front bay, but decided not to for the extra weight to consider (which in turn you lose in other cargo) and fuel. While on one of our first trips out, we talked to full timers in a FW with a generator that ran on propane. They had to carry extra, tall, canisters in the bed of their truck to fuel up their generator. Forget that we said! We decided to stick with our Honda 2000 genny which has served us well with the exception of AC. Since then we've added solar panels, extra batteries and can run everything in our FW except for the fireplace, AC, and built in vacuum. The time of year we travel and where we travel, works well, which is usually in the fall and in the Rockies. Last year we took a trip over the Labor Day weekend near Jackson, Wyoming, and it was hot. No AC, since then we've talked of a larger portable generator or an extra one and pigtail it to the other, to support the AC.
Before getting our FW in 2010, we were on the verge of signing the line on a Class A. We had a Jeep to tow behind and thought it was our dream. I was the one undecided, going back and forth to the dealer three times looking at the motorhome and not really ready to commit. Then, on one of those trips, while sitting in the motorhome, my husband asked where I was going to put the garbage can. The garbage can? I'm the type of person that I like everything neatly put away. The garbage can? I began to look. Not one place could fit a decent sized kitchen garbage can. Well, he said, you can always put it out on the floor. No way. Then I began looking at the storage and where were we going to put the dog food? The cleaning supplies . . . on and on. We realized that there was not that much in storage inside. We left. The salesperson was not too happy, but hey, we're the one's footing the bill. The next day we went to a FW dealership, found what we wanted and went back and forth to be sure, even having the salesperson bring in the slides so we could see if we could move around in it with the slides in (we stop en route at rest stops to eat and sleep. So we wanted a unit we could be in with the slides in and we could!). We have never looked back. We LOVE our FW and have added many after market upgrades since. The unit we have is quality built and well worth our keeping till we can't travel and hook it up any more. We went through the learning curves, but never regretted our decision. What we did learn is to be sure you have enough truck to tow what you purchase. We initially had an F250 V10 which towed it ok on flat land but only got 7mpg and had little power up and down mountains. We installed air bags on the truck but blew those several times. We traded in for a F350 diesel dually and what a HUGE difference. It has the power we needed along with fuel efficiency.
Lessons learned - take the time to get the right floor plan and a quality unit for what you can afford, even if it's used. There are a lot of quality used units out there. Get an inspection done. Get the right sized truck too. That part you'll never ever regret especially when you hit the Rockies or have to accelerate suddenly while towing.