Bulldog isnt adjustable as far as I know.
An adjustable reg, that is similar to a preset, would be the Nitroduck Extreme...cheap at around £75 from Pheonix....and a very good reg.
Any reg, should come with burst disc, at least one gauge and fill nipple...along with an o-ring in the bottle side.
Just screw the reg, hand tight into the bottle and off you go...dont use loctite, you will regret it...