Hi Tosh,
Matt did a really good DIY guide, lots of good links in there.
As it is the backpack you are thinking of using, I would recommend a spare battery though, they can vary in how long they last, but will only give 4 hours of continuous use and they take well over 24 hours to recharge completely.
So a spare means you can have one charging constantly, even through the cigarette lighter.
These batteries are not designed to be ran flat, so pushing them too far will drastically reduce there lifespan, mine for instance will only now give me an hour or so of use, but perhaps it was a bit of a dud to begin with
I use a large leisure battery, but that wouldn't be a lot of use to a backpack user
There are a few backpack users on the other forum, Lewis Doubtfire is a keen advocate of the backpack, he uses both forums, and there are a few others too.....whose names have completely left me :
Try a few PM's to them, they will have loads of relevent info as they are hands on users (as against suppliers) (ok, ok, I know, some suppliers are also hands on users....just in case anyone decides to point out that fact to me
)
But as Matt said; R/O system (I have the same one as is shown in his links) A large water butt (local garden centre for mine) and up to eight 25 litre containers........er......or maybe loads of smaller ones, rather depends on how you will be refilling the tank on your back.....the hands on users will give you the best info for that bit methinks
Your poles, lots of choice there, depending on the depth of your pocket.
Brush; go for the domestic size brush, Ionics do a good one but might need to be adapted to fit whatever pole you get (unless it is the same fibreglass poles they use) I prefer the single filament ones, much easier to keep clean than the flocked bristle brushes, but each to his own on that one.
Make sure you have a 'jetted' brush though, whether it is a fan or needle type jet doesn't matter, though the 'fan' type may well use less water so that may be worth a thought because of backpack & volume of water you carry around.
No time for more waffle, time I was at work!
Ian