If you can afford it, go AC/DC. You won't be disappointed. As a former welding instructor, and recently retired from my welding/fabrication business, DC would be preferred over AC. AC machines are more reasonably priced, and for the occasional "stick it together" operation, just fine to deal with. DC machines are much more versatile. I have to disagree with one poster regarding MIG over Stick. When it comes to weld strength, I'll put my stick welding up against ANY Mig weld, ANY day. I have a couple of MIG machines, a Miller Spool gun for aluminum repairs, and a Digital Lincoln for steel MIG welding operations.
These are the electrodes I use the most. The Lincoln 5P+++++ (E6010), ESAB Atom Arc E7018, and the old "burn through anything E-6011. Of course I have many different electrodes, for different purposes. For extremely high strength welds I use the E11078.
A quick course in Electrode identification: The numbers imprinted on the rods identify them, i.e. E= Electrode; THE FIRST 2 or 3 DIGITS tell us the strength, thus the 60=60,000 PSI Tensile Strength.
THIRD or FOURTH DIGIT 1=Welding Postion, and in the case of 1 it's an ALL POSITION electrode, 2= FLAT AND HORIZONTAL ONLY, 3=FLAT ONLY.
The last digit tells us the Welding Polarity and Flux coating composition. You can check out and get all the specs from your local welding supplier, or, the AWS web site.
An E6010 rod is for DC Reverse Polarity only. Won't work worth crap on an AC machine. The E6011 will work on both the AC or DC machine. Much easier to use for the novice.
WELD PREPARATION can't be stressed enough. The cleaner your weld joint, the better the weld. Also, for cleaning slag, I use a 4 1/2" angle grinder with a wire wheel. Works great, saves time, makes the job look better.
If I can be of any help to anyone, please don't hesitate to ask. I'm a newbie to this forum, but not to the welding/maintenance world.