I still stand by my recomendation of the 6013 rod. But If/when you get the welder, go to TSC or where ever and pick up a pound of 6011, 6013, and 7014 and TRY each for yourself.
IF you get an AC machine, you CANNOT use the 6010 rod. It is DC only. BUT 6011 is the AC equivellent pretty much.
6010/6011 are both HOT rods with LOW deposition rate. That means they burn in deep and dont deposit much filler. It isnt hard to burn clear through 1/4" metal on only 100A. But 6013/7014 it is almost impossible.
Also, due to the low depsoition rate, fit is alot more critical. Peices must fit tight together. No rough torched ends with gaps here and there. Wont weld good at all.
6013/7014 are very similar. (in case you didnt know, the first two #'s indicate the tensil strength of the weld. 60= 60,000psi....70=70,000psi). But both of these rods are easy to weld and "contact" type rods. They have a higher fill rate, which doesnt mean as much penetration, but they can also fill larger voids and cracks much easier, like using a torch to cut ends instead of a bandsaw. They are also much easier to start/re-start.
7018 I'd stay away from for a home "hobbiest". First of all, proper storage is everything. (oven to keep em warm and dry). And 7018 is a DC rod as well. You can get 7018AC, but it doesnt weld as well as 7018DC on a DC machine. And again, the storage. Also, with 7018, when you stop a weld, the end glasses over. You have to take the electrode out of the stinger, and drag the tip across the bench a few times to break the "glass" just to be able to re-start. A real PITA for just a hobbiest.
Again, my best advice is to get a little of 6011, 6013, AND 7014 and try em all for yourself. Personally, at home, My "GO-TO" rod of choice is always 7014.