Just about all the straight trucks you see on the highway doing OTR expediting are independently owned, by either an owner/operator or a fleet owner. They are leased to the respective companies labeled on the truck, and are not owned by those companies. So, if you want to get into a straight truck without owning it and do expediting, you will need to find a fleet owner to drive for. The EO classifieds are a good place to look for a driving opportunity. The pay and whatnot varies as you will work this out with the truck (or van) owner.
Can you make a living doing expediting solo? Yes, as I have been for the past 3 years. I do, however, own my truck and manage my own business. If I were only making a 30% cut as a driver for someone else though, I would not be making it or would really have to bust my butt to make it. I average about 1500 miles a week running solo, but all the truck revenue is mine as the owner. I subtract all my running expenses from this, and that's my pay. No, I don't make a fortune. Anyone who does expediting and tells you they do is a liar.
Probably the only way to make any money driving for someone else in expediting is as a team. The truck needs to be leased to a good company that will give it at least 3000 miles a week. I would get your wife to go with you that way you don't have to split pay 50/50 with so to say "me" as a teammate. You keep the money in your family.
Things are sort of unstable in the expedited freight business right now, so you might be best off sticking with the 18 wheeler for a while.
Take care-
--Weave--