OK, so camelbaks, not available as private label in this country, although blank ones are available, for printing elsewhere (which I am not keen on as 1) it's too much effing about 2) any mistakes will be taken out of the pool of available bottles.
Zefal ones are reasonable[1], per unit, for single colour, have requested 2 colour costs, along with setup costs etc. As previously mentioned minimum order is 250 for Zefal, but I may bite the bullet (if I get enough interest) and order that number anyway, keeping some as stock.
Also awaiting some samples from the producer of previous bottles(Wildoo), wide necked, screw top ones, to assess their quality.
further details as and when I get them.
[1] FWIW the individual cost of custom Zefal bottles, with single colour is less than buying them with Zefal/SIS/whoever branding on them.