I've used Valley National Gas several times ... they used to be called something different .. and have since become a bit expensive. You might want to price shop & call around town.
Right by the old Buy Fish Now @ Daniels & Tree Line BLVD.
http://maps.google.com/maps?client=s...5655711667785#
It'll probably run you about $120 or so for the initial bottle ... a 5 lbs bottle usually lasts most small tank owners over 6 months ... I ran my 20 lbs for about a year, and it was turned way up, and the fitting was leaking.
Refills are fairly cheap .. i think i paid $30 for a 20 lbs refill ... the bottle & regulator is what costs $$.
regulator:
http://www.aquariumspecialty.com/cat...roducts_id=460
The milwaukee is decent .. there are way better ones out there, but some they get quiet expensive.
Good Luck!