I suggest You get a "stick" 220 volt machine 180 amp or 250 amp. You are asking for the "best", I am suggesting adequate and economical.
I would buy a used machine off eBay or craigslist. These machines are heavy, so get one close enough to pick up.
Lincoln Idealarc 250 or Miller Dialarc 250 are rock solid light industrial machines. There are many other brands, these are the most common.
The next step below is a Lincoln 225 or a Miller Thunderbolt. Once again there are many other machines that will work fine, these are the common ones.
You coud do this job with an AC machine or a DC machine. AC machines are a bit cheaper.
As to older machines, if it works it is OK for the work You mentioned.
I take it this is non code work in Your home/farm shop. Residential locations usually only have single phase power available. IF YOU DON"HAVE 3 PHASE POWER, DONT BUY A 3 PHASE MACHINE.
This job could also be done with a 250 amp MIG machine, they are more expensive and need to be kept in a dry environment to keep the liner from rusting.
If You don't know how to weld, You will have to learn. The easy way is an adult education program at a vo tek school. The hard way is read the books and teach Yourself. Both methods require that You practice a lot.