If you can stretch the budget a little, a cheap DIY WFP system will be money well spent. A water filter (£100 odd), A backpack (£200 odd) a static IBC (£40) and a small sack truck and some 20 litre water drums (another £60 - £80), and then a cheap universal pole, or even a DIY pole (£60 odd)

So less than £500, and you've got a (Basic) WFP system. No ladders, and you'll work much faster. You'll still need some basic trad gear for insides, but not nearly as much.