get a 1.1 litre High pressure (850psi output) preset
the best regulators are said to be Crossfire.
However, many people use PMI (the EVIL logo bottles) or centreflag (often annodised a nice shade of purpley blue)
if you want the best advice, get a stako bottle.
most of these come with a protoyz reg, which while being unglamorous, will work fine. also, the bottle will be a great match for the marker (lightness)
I know what I'm doing (done!)