I've just got a long cylinder off Harry with QF and gauge. Can't remember what it was off hand, but think it was around £200.
My probe is vertical on the gun. It's a faff, but preferable to screwing on and off in my opinion. Ideally I'd like the probe to be horizontal, but i guess that depends on the reg thread, which is only going to be 180 degrees either way.
BFTA/NSRA County Coach
CSFTA Chairman/BFTA Rep