Good advice given above...
Check to make sure that CTS isn't the reason your coolant is low.
If it's gone there should be a geyser of coolant coming out somewhere. Your gauge would also...er...fail to work.
About the rear leaf springs...that is a project you really can do by yourself. I know it sounds scary, but rest assured it is not.
1. Block the front wheels and then jack the frame of the bus up until the tires are no longer touching. Place jackstands under the frame.
2. Place a jack under the differential and put a jackstand out on each side. The stands don't need to be touching, but should be close.
3. Unbolt the u-bolts from each side. You're looking at 4 nuts each. Your new grinder might be quicker than using a wrench anyway and you're not reusing the old u-bolts.
4. Lower the axle down onto the stands with the jack. It shouldn't have had to go more than maybe 1-2 inches so brakelines and the driveshaft shouldn't be an issue, but pay attention just in case.
5. Grind the heads off the shackle bolts and the spring hangers. Drive them out the otherside with a punch and a BFH. If worst comes to worst just start hacking with the grinder until the springs come free, even if it means cutting the spring. Just don't damage the hanger or shackle.
6. Hang the new springs with new greased shackle and hanger bolts. Torque them down good, but it should be a self locking nut. Don't overdo it.
7. Jack the axle back up off the stands and install 2 new u-bolts per side. I want to make sure you remember to use NEW u-bolts. Hammer those suckers down...you're probably looking at 200-250 ft lbs each on them.
8. After a hundred miles or so just retorque everything.
I can't remember whereabouts in Minnesota you said you were, but your best bet is probably going to be Husky Spring in St. Cloud. They will build you a new pack or even just rework your old one if you want. They will also bend you up the u-bolts you need and will be able to bush the springs for you. We have one of their shops up here in Virginia and they've done good work for me. The owner of the company is a good guy and I don't think you will be disappointed with the service and pricing you receive. [/shamless plug]