Here you go I like this style all tanks under $100 they where $60 a year ago I guess people like them.
heres the store link with choices of tanks .
this one has a tap on the bottom already for a gas line Id put two together side by side you can even use a paint technique to make them look like copper tanks
Size: 9.5" length 5" diameter
Bolts are 5-1/2" center to center
Holds: Approximately 2.7 quarts
1/4” N.P.T | Return and Vent
1/4” N.P.T | Feed
heres haw to make it look like copper