Not sure why you would buy one when you already have one on your MH. While it takes a little work to get up to 115 for my previous front tires, it's not that hard. Buy a good air line, a dual chuck, and quick connects that go on you air line/tank drains and you're good to go.
Only tire I know of that requires 150 is on a jet airplane.
A 400HP compressor might be overkill??? - JMHO
Just finished No Easy Day by Mark Owen; it's the first-hand account of the killing of UBL. It was a good book and I really enjoyed it.
Prior book was The Amatuer by Edward Kline, a book about President Obama. It was a very imformative book which I also enjoyed.
Look at a used Grand Vitara, they are cheap and plentiful so they are easy to find. The 4WD models are very durable and hook up easily even with the auto transmission. They are fairly small for an SUV so you can pull one with most any motorhome.
We had one as our 1st tow car and it served us well until we decided to pull a larger vehicle.