I don't believe you can speedliner your van floor for just £70!!
You can certainly use protectakote for that price, but it is not a patch on speedliner which is the rolls royce of floor protection.
After that it would be fibreglass, followed by the less durable Protectakote.
Peter fogwill is up in Scotland, he is also a supplier of Water Fed Pole systems, check out his website as a comparison.
http://www.window-tools.com/A thing to remember is that when you look at what you actually need, it can be done for considerably less than the likes of Ionics will do it.
This isn't to denigrate Ionics or any of the other major players, they are all highly professional, leaders in their field and will supply and fit you with a top class system.
Van mount:
Water proof floor, either Protectakote @ £70, fibreglass @ £100 or top end speedliner (expensive!)
Caged tank
Battery
Pump or pumps if more than one man band.
ditto hose reels
Poles (go for the lightest setup you can afford, and looking at the prices you quoted from Ionics you can get top flight poles for way less than that!)
Pole hose.
Lightweight brushes
And hose, personally I'd recommend microbore.
I think thats it....presumably you already have an R/O setup?
If not, then include that in the list.
I can understand you not wanting to DIY it, and if yo uwere preared to spend close to 7k for an ionics setup, there are other suppliers that will sort you out a system for considerably less than that...but Ionics won't be ripping you off.
Ian