yeah david, really consider the air bags if you can.
I have a fleet of Outside Broadcast vans varying in size from 2 to 42 tonnes, the ones with air bags give no trouble at all, the "sprung" ones are a full time job tightening bolts, rewelding cracks......
With optical stuff the last thing you need is to open the back up after a trip and find you primary mirror has been making like a frizby along the way
Don't worry about a bit of wieght either.....makes for a smoother ride.
cheers