Yes, I know, but bear with me! 7ish years of trad work that I built up from scratch on my own, a couple of back injuries has severely hampered me over the last 18 months, to the point where I may well be done with hauling myself up ladders (though I'm only 32!), or it will take longer to fully recover (no longer viable, financially) due to the muscles being constantly in use walking up and down ladders. I'm loathe to give up on my round (I've already reduced my round down to what I hoped would be a more manageable level) and love working outside and being self-employed, so while being forced to switch to WFP, I also want to embrace it. I'm looking at WFP for tops, trad bottoms while I get used to it and get up to speed.
So, on a minimum budget (I'm already sweet talking a family member) and needing to be set up as quickly as possible to be able to get working again, specific advice is needed:
I currently use a Renault Clio hatchback for my two ladders (an extendable aluminium for first floor, 6ft single for ground) which I need to somehow use for a backpack system. I suspect this may not be possible - standard car boot only half opens due to the long ladder. I could leave the large ladder at home meaning the boot will fully open. Or maybe put the backpack on the front passenger seat! It's a 3-door btw.
I've read about Partners and Berlingos on here, but £1k+ for a van will be the next step once I can prove I'm up to the task of WFP, health-wise.
I found a mention of the WCW Backpack starter kit at
http://www.windowcleaningwarehouse.co.uk/shop/index.php?option=com_aceshop&route=product/product&path=131_248&product_id=1377, which is pricey but it'll arrive next week and I'm good to go, though I don't know a thing about the various products within the kit. I have an excellent customer base and get on with them very well, and will explain to them about WFP and why I've changed so I need my equipment to allow me to do a good job at a cheap price for now. I know the Gardiner brushes and CLX poles are highly recommended, but again, that's an upgrade for a later date - I'm looking at the urgency of working more regularly and consistently ASAP versus waiting any longer for something more.
It comes with 4 drums, which obviously won't all fit in the car, but remember I'm only doing a few houses a day at the moment, and WFP will be tops only. My work is also very close to home so if I do manage to empty one or two drums, I can go home and change the drums over - this may be simplifying things somewhat, as Surrey is a hard water area. No I do not yet know what the TDS is, there is a TDS meter reader with the starter kit above!
This means I'll need an ro unit, which doesn't appear to come with the starter kit, so I'll need a good one from somewhere, recommendations links and prices most welcome. And I've been searching for some sort of guide of how to put it all together without finding one, but it's ok, the starter kit comes with a DVD....

Have I forgotten anything?
Thanks for reading, and thank you for your help