Caveat: you've done more TIG than I have, so I'm just sharing my research here... (my welder's a few weeks out). I talked with CK this week for exactly this reason; here's what I learned:
They have 2 air-cooled Flex-Loc torches (the style with the swivel head); I didn't look into their other flexible-head torches. Flex-Loc has 130-Amp "Series 2" that uses size 9 fittings, and 150-Amp "Series 3" that uses size 17 fittings. The only difference between the torches is the head, which is interchangeable between the two sizes. (No idea how easy that is.) E.g., FL1512SF is the part number for the Flex-Loc 150-Amp, 12-foot, with Superflex hose, and no gas valve (about $145).
You can get their standard hose or their SuperFlex hose, which everyone raves about. Hoses come in 1-piece or 2-piece varieties, but newer machines use the 1-piece. Mark at Everlast recommends not getting the 25' hose unless you need it, because it can affect arc starts and require higher power settings at the machine.
You need an adapter to convert the combo gas+power to a Dinse connector with a quick-disconnect pigtail for the gas. Presuming your welder has the QD for the gas and a 1/2" Dinse, the part you need is SL2-35QD (about $46).
Per Mark at Everlast, this chunky adapter has trouble mating fully on some welders, and some "field modification" may be required so it'll seat fully. (This is an issue on the 210EXT; I don't know about your model.) The first 210EXT I received included a male-to-female extender block that I think is designed to fix this issue.
Weldfabulous.com is often mentioned as a source. Everlast is also reselling CK products, and Mark's the guy to talk to.
http://www.everlastgenerators.com/contactus.html
I hope this helps!
Cheers,
Richard