If your need is full hook-ups AVI is less convenient to the action than Riverside, and a lot smaller, but adjacent to a nice casino. Virtually all the casinos allow dry camping, and Riverside provides a free shuttle to its casino (across the street from the park), and on the main drag (where all the casinos are (except AVI).
Donner Pass (I-80) is a big, long hill that takes a beating every winter. Trucks chain up, cars slide and skid, and RVs crawl. In the summer the CDOT usually repairs the road, due to the heavy toll the traffic takes on it during the winter. It's an OK drive, but can be tough depending on your ability to climb hills, pass a slow moving vehicle, or crawl at a slow rate.
One of your greatest resources will be www.rvparkreviews.com both for planning, and for information gathering. You should have an idea where you want to go, find campsites which are appealing, call and see what's available and when. Then go back and flex around the higher priorities on your list. That is, if Colter Bay (WY) is available on a certain day, go there and work Yellowstone around it. There are some locations, of course, that have multiple campgrounds, so you might have the settle for something not as desirable to get to or from the more desirable. Try to be flexible when planning, that way you will have your trip planned, reservations made, and no worries on the road, but to get there! The Next Exit is also a great resource, which allows you to find gas, food, etc. at each exit on Interstates.
Having been an editor for RV Park Reviews I have become so used to using the site that I would find it difficult to utilize any other. I have noticed, however, that there are some people who zero in on certain things they prefer, and judge/downgrade a park because it might be lacking (eg. playgrounds, dog walks, etc.). So, if you read each review carefully, see what the likes and dislikes are, look at other reviews for the same park, you should be able to ferret out what your opinion of the park might be.
I would travel I-40 in the warm weather, but if you insist on the 10, I'd look at Usery Mountain Park or McDowell Mtn Park. They are both part of the Maricopa Park SYstem, each are not crowded, and are well situated in the Valley of the Sun. If you want less traveled and more remote, at least in Arizona, check out the County Parks (Maricopa, Pinal, etc.), they offer a lot, for less money, and have retained much of their natural beauty.
Some people like train rides (me), and some don't (wife). Some people like riding thru the high desert, some don't. If you don't know either of these, don't spend the xtra $$. It was fun for me, but she said she was not against walking back from the South Rim.
Coeur D'Alene is a fun town, with a very pretty lake, and a great little college. Blackwell Island RV Park is one of our favorites, as it has it's own beach (which includes a segment for dogs). Much to do around the area, including mine tours, sidewalk sales (weekly), and interesting non-franchise stores throughout town.
Whenever we go to a place like Branson, Gatlinburg, etc. we choose the nicest place we can find between the destination (town or city) and the interstate we drove in on. By doing it this way we: 1. don't end up driving through all the traffic with our rig; 2. don't end up in the middle of everything, and tied up in traffic when we want to go to dinner.
We budget for $50, but hope for less. Certain places we like to go are more, and others are less. And, it's not always the "nice" ones that are more (eg; Seven Feathers in Canyonville, OR is about the nicest in the West and is under $50). And, some places, like Lucky Star in Concho, OK are free!
The category of parks you should be looking at is County and State parks. Just google Arizona counties, then check each county for parks. Maricopa and Pinal counties (Phoenix area) have fabulous camping areas, which compete with commercial parks. You can start with Usery Mountain or McDowell Mountain, both great places to stay, and beautiful, natural settings.
Whenever in San Antonio we stay at Buckhorn in Kerrville. We don't like the challenge of living in the city, but enjoy spending the day(s). And, there is not a nicer place to stay (in the area) than Buckhorn. You just have to time your driving to avoid commuter traffic.