$40-$50K does put significant limits on your choices. A budget in the mid $60s range would expand those choices a lot, but you do not want to over extend your finances. Careful shopping you will find that units with an MSRP of over $90,000 can be found for an actual sale price of something in the $60s. Getting all the extras for free or discounted depends on your negotiating skills and how bad the salesman wants a sale.
Yes, a generator is typically offered as an option, at least on mid and higher range units.
Newer 5ers now (again mid or higher) typically come with, or have option for, push button leveling just like a MH. Hitching up is not difficult at all. The hitch is essentially self aligning. The pin will slide into the hitch slot as long as you are within an inch or two of being aligned.
Backing is one of those things hard to explain. For some, it comes so easy it is hard for them to understand why others can't do it. For me, it has always come easy. For a good friend of mine, he has struggled with backing any trailer all his life. But I do feel anyone can do an adequate job with practice. When I bought my 5er I bought some cheap orange cones from Walmart and went to an empty local football stadium parking lot on a Sunday and practiced until I felt I could handle it.
