Hey George,
Re the exhaust....
That's pretty much what I did... the green monster sits on a wheeled chassis, it has a built in exhaust that goes down from the port and travels the entire length of the chassis forward, below the axles.. at the 'front' it travels upwards about 3ft in a 'silencer' then into a 90 degree bend that is connected to a flexible coupling of sorts and then goes to a wall mount vertical 6" pipe .... the good side is, being pretty much self contained, it can be re-sited for major work and running etc... because the first half of the exhaust is integral to the chassis, it can be run as is and the final outlet can either be vertical, or 360 degrees of choice by using the elbow/slow bend... it has been pretty handy so far, just not much fun moving 2t of steel around at a whim!
Cheers,
Ed