Sounds like a good piece of equipment to start off with. I at one time had a full time mobile service business for heavy trucks and still do it on a part time basis. First thing you need is something to put everything in. Personally I'm a big fan of cube vans. They have better turning radius than a P/U truck and tend to set closer to the ground. Distance from the floor to the ground is something to keep in mind as you may be going in and out of it a lot. I wish Chevrolet still made the G30 with their own box. That's what I have used for years, a 1988 G30 12 foot cube van. What is really nice is it has a 10,000 lb GVW so it did not need DOT numbers and I didn't have to worry about going over the scales. It has a very low floor due to the fact it has no real frame rails past the cab of the van. Back when they made them they had a unibody construction where the floor was a intergral part of the frame structure. The big downfall was they were a all steel body and living in the rust belt the rust monsters tend to attack them. Something to keep a eye out for is a used utility company service truck. They usually have everything you need, air, generator, shelving, etc...
Other than a vehicle or trailer put some thought in your shelving and storage. Take it from me, it's easier to design it right the first time then redoing it a couple of times. Get a good road chest tool box, I use two Snap On road chest. Other than that some jacks, stands, air tools, hand tools and a good selection of hardware and parts and you will be up and running in no time.