You say metal plane how thick is the metal going to be if 16th thick going to be awfully tough to do if thicker there is not a ton of difference in Flux Core welders mostly the duration of the weld before letting the welder cool down. Argon shielded welders give a much cleaner weld ( less spatter and clean up ) and easier to use unless out in the wind. The one I purchased has the option to add the argon if I so desired.
When I was younger was building a boat trailer from galvanized pipe arc welding in the winter time in a closed garage woke up the next morning thought I was going to die could hardly breath. Back then never heard of galvanized poisoning but I learned the hard way of what it was.
I basically hate flux core welding, it is like brazing to galvanized metal . if anything make sure it has the option to hook up a tank so you can use standard wire with Argon or mig mix gas, much cleaner welds.
There are many welding machines and a lot of them are really good at what they do, and some are pretty bad and you should always find out about them so as not to waste your time and your money. My father taught me to weld when I was 12 years old and it happened that he burned himself badly due to a malfunction and poor quality of the welding machine. To prevent this from happening, you need to use good welding machines and you can find out about them on the website about the 10 best reviews of welding trolleys. It explains about some of the best carts that you can safely use without injury or burns.