I had air helper bags in several trucks in the past and I found plumbing compressor permanently unnecessary. Well build system will hold the air for weeks and if you need to add air you usually do it before start of the drive.
I did love the dual control gauge/valves and having tire valve installed on the supply hose, I just connected portable compressor to it and adjusted with valves.
For your set up you will need 2 of those gauges, but single compressor.
Check craigslist and ebay as I bought set of 2 bags, compressor and gauges for less than $200.
Your front will need custom bags, so you might have to buy those new, but rear bags I've seen were all the same, only with different brackets for different vehicles.
That said I had front air bags on older Bounder. They went inside the coils and were always pain on the behind.