Ok, I JUST got back from a 1800 mile trip. Fresh off the road here's my advice, take it for what it's worth:
1. Plan for the worst case scenario and add 25% in finances to cover those expenses. I had to replace my friend's rear shoes and drums on his Explorer so we would have a safe trip to the bus 6 hours away. He hates to work shoes and drums, but it's no problem with me, I'm a mechanic. 3 hours later we had new rear brakes. 12 hours later we had TWO emergency stops @ 80 mph!! due to California highway construction and NO warning signs until AFTER cresting hills.... IDIOTS
2. Make lists of needed supplies for trip. I made numerous lists of things I needed to bring with me then shaved it down to what would fill my Alice pack on the airplane. You have the bus ready and are limited by what it will carry. Think about the weight. The heavier the load the tougher it will be for the bus to go over mountains. MORE IMPORTANTLY it will be tougher on the brakes slowing down on the other side of the mountain. Brake fade SUX!!!
3. Get a trucker's atlas. They run about $60 at the truck stops but are WORTH IT!!! Those atlases give you information regular maps don't. The information will help guide you to service areas, reference national truck stops and repair shops. Usually there are 1-800 numbers to help you with mechanical emergencies.
4. Keep your speed below 65 mph. I don't know the top speed on your bus, but staying below 65 - sweet spot being about 62 mph or so - will help keep the tires cooler and help prevent a blow-out. Older tires are more susceptible to heat related blow-outs.
5. RELAX DANG IT!!!!!
Just remember, there are certain things that are outside of your control. If you take care of the things that ARE within your control you'll be better able to deal with the others.