You pretty much have a bunch of stuff already.
even if you have a spool gun getting far from the welder and into strange places never will be like stick where you can bend the electrode and flex the lead.
I have carbon dioxide for plain steel wire and carbon dioxide 25 argon 75 for the dual shield. One guy at a welding shop says the self shielding wire is virtually the same as the dual shielding just the gas or lack of it. he is the owner and won't stock the dual shield. I think the logic is if your life is in danger if the weld breaks you use the dual shield.
I have a Westinghouse 200 amp mig machine which isn't pulse or anything modern. I find for aluminum heating the starting point with a torch makes much better results.
The dual shield makes tiny worm holes things unless perhaps you just opened the package but that was long ago. It puts into the metal more heat per amp draw from the electric company at least seems to me that way. 7018 which I think might be the stick equivalent of dual shield seems to be amenable to heating with a torch after laying around.
The mig or wire feed processes with a primitive machine take a while to get burning in well and more bigger creator at stopping than stick. If you put your stick on the foot pedal or perhaps have a hot start feature things probably lean more to the sticks.
I never could figure out how to make the dual shield work overhead except for a small tack. Perhaps some pulse feature is needed the instructions claim all position. I can't do very well with 6010 overhead but certainly can do better. We are talking relatively diameter in both cases.
All processes can get frustrating. with the fire feed processes the contact tip in the gun can stick to the wire and need cleaning similar to a oxy acetylene device. The sticks can stick and the flux can keep flaking off as you try and trim the rod back and the tungsten can contaminate causing frustration. The mig can also make a bird nest I think they call it if you don't stop fast enough after the tip sticks.
Fran