Yes, spattery a bit more but if you can get it, its far cheaper than any pro mix and great for practising on. A little spatter on a job like this is not really that crucial i feel, I never had that much that it was a pain - its not like chalk and cheese.

+1 on the wire feed, this must be set right first off, as you said, too low will give a weld but damn, things will get hot and can lead to a large heat affected zone and distortion etc which can easily be avoided.

Current is pretty easy, if this is like 4mm box then any hobby welder in the 150-180A range will likely be on full-tilt, but getting the wire feed and motion speed right takes a little practice.