I would think just buy 4-25 foot dry lead lines get some fitting and waalah or is it easier said then done?? LOL I've seen you can buy a max of 25ft but if you are a portable tig welder I could see how I would want it to be about a 100ft
If You are going touse HF You want the HF unit on the end of the torch lead and run the rest in cable & hose. The cable & hose is the most sensible way to go anyway for a long run.