I put the regulator and needle valve together back before CO2 equipment became more widely available in Canada...
CO2 tank is your standard 5lbs aluminum tank available at OxyPro. Refills cost ~10 bucks... all they do is take your tank and give you a filled one. Takes about 5 minutes for an exchange

. No fuss about inspection fees and such like you would have if you buy your own tank.
Regulator is dual gauged and made of brass. The output guage is made to measure pressure in the lower ranges ~20psi. Needle valve is attached to the guage. I got that valve from Swagelok for ~50 bucks

.

$75 OBO for tank. $50 OBO for regulator and needle valve. $110 for both.
Thanks for looking!
-Rich