churchward

Any bottled Co2 source will be OK. It gets expensive if you want to use more exotic mixes (like Argon and the like) for specialist work such as stainless steel. Sealey do a 1kg Co2 refillable bottle you just exchange for a full one (just paying for the gas for refills) when you need to just like a calor gas bottle on a boat. You can check if there is an agent in your area. I tend to weld with Flux wire (gasless) MIG these days and is more convenient for welding outside where a gas feed system can be blown away from the weld bead. I also use stick welding particularly for thicker stuff as I find it more suitable and in any case I find it simpler and I just like it. I do use gas for particular stuff when it calls for it.

I have used both. For a while, I used a Pela when the pump broke, and still have it and it is useful sometimes. I prefer the hand pump though

Smokeless fuel is not entirely smokeless particularly when fresh amounts are added to the fire or it is first lit. Once the coals are hot and fully burning there is little to no visible smoke emitted.