want one to charge aa410 where is best place to buy and what size as near halifax as poss help
You could give Robin Hood Watersports a look. I don't know whether they're your nearest but they're out your way. Prices for bottles are very good and they stock both new and recon. You'd have to source the gauge and hose elsewhere though.
Robin Hood Watersports
Alternatively, stick an ad in the wanted section on here for a second-hand bottle.
Paul.