You can penny pinch and waste time and money building your own or you can go out and buy the Omnivac. Its a superior machine and will earn its keep very quickly.
If you need spares or modifications, Glynn H or the lovely Andrea, from Omnipole will sort you out in seconds.
I have the full set up including omnivac camers, generators etc, in fact its all now trailer mounted (sign written) as I use it at least 2-3 times a week and I charge top dollar for a so far unique service. Be professional earn professional money.
Don't get me wrong but I'm a business man not an inventor. I leave that to people with the knowledge and skills. The Health and Safety really don't like bodge jobs that fall apart injuring you or you staff. There are many benefits to owning a professional system in my opinion.