For your gas line, there are a few options. Duotight Stem adapter DUO134 can be used on existing vinyl tubing, or combo stainless barbe to flare adapter KEG620 and flare to duotight adapter DUO106.
If your regulators has 5/16" hose barb, you can add a gas-in ball-lock quick connect KEG710 or KEG730 & KEG640 to your existing vinyl tubing. Then join with either FE133 or KG502 and adapter DUO100 for 8mm EVA tubing.
The cleanest and toughest option is to replace the entire on/off valve of the regulator with D1121 followed up with DUO106 . The hard part is removing the stock valve, it will likely have thread lock sealant and you'll need to heat it to loosen, either with a heat gun, or possibly pouring boiling water over the threads.