Is there a conversion kit for this......

[MAC702]

Both of my VS feeders are capable of running SMAW ....

I'm sure you meant GMAW.

[Jolly Roger]

Both of my VS feeders are capable of running SMAW or FCAW and I was welding 20ga today with .035 NR 211 MP using one of them. You won't get as good a result with cc as with cv and it will take some getting used to. If you look around you can find them pretty reasonable. I gave 450 for my Hefty cc/cv and ln-25 together.

[MAC702]

The processes are different. Stick uses a Constant Current source, while MIG is a Constant Voltage source.

You can get spoolguns, like a ReadyWelder, or expensive voltage-sensing portable wirefeeders but these are usually for flux-cored wires, and not the thin stuff that MIG is generally preferred for.

I've never actually used a ReadyWelder spoolgun, so maybe do a search for more specific info on whether or not they are worth anything.

I have a Miller Econo-Twin Arc welder, can I use it as the power source for wire welding? Is there such thing as a mig accessory that will attach to an arc welder for power?
Thanks