You can reuse that regulator.
I'd either get an Aliexpress 4.5K .2 liter tank, or one of my tanks(much smaller).
You'll need to get a first stage regulator that has an output of 900 PSI or lower, but other than that, nothing crazy.
https://www.aliexpress.us/item/3256...2b4-10a2-44b6-8120-2975116d8d5f-5&pdp_ext_f={"sku_id"%3A"12000030164436586"%7D&pdp_npi=2%40dis%21USD%2142.14%2131.6%21%21%21%21%21%402101df8a16683784113895262e5d7e%2112000030164436586%21sea&curPageLogUid=8fm0i1Cx76MH
https://www.aliexpress.us/item/3256...2b4-10a2-44b6-8120-2975116d8d5f-2&pdp_ext_f={"sku_id"%3A"12000030776652969"%7D&pdp_npi=2%40dis%21USD%2138.83%2118.25%21%21%21%21%21%402101df8a16683784113895262e5d7e%2112000030776652969%21sea&curPageLogUid=BzI2DbkmD1Kh
The gauge on the tank is to tell you how much air you have.
I'd either get an Aliexpress 4.5K .2 liter tank, or one of my tanks(much smaller).
You'll need to get a first stage regulator that has an output of 900 PSI or lower, but other than that, nothing crazy.
https://www.aliexpress.us/item/3256...2b4-10a2-44b6-8120-2975116d8d5f-5&pdp_ext_f={"sku_id"%3A"12000030164436586"%7D&pdp_npi=2%40dis%21USD%2142.14%2131.6%21%21%21%21%21%402101df8a16683784113895262e5d7e%2112000030164436586%21sea&curPageLogUid=8fm0i1Cx76MH
https://www.aliexpress.us/item/3256...2b4-10a2-44b6-8120-2975116d8d5f-2&pdp_ext_f={"sku_id"%3A"12000030776652969"%7D&pdp_npi=2%40dis%21USD%2138.83%2118.25%21%21%21%21%21%402101df8a16683784113895262e5d7e%2112000030776652969%21sea&curPageLogUid=BzI2DbkmD1Kh
The gauge on the tank is to tell you how much air you have.