When picking a welder, you need to consider where you will be working.
Do you have 220V available or within 50 feet? If so, you will want a 220V welder. Dont skimp on this.
Yeah people will say that their 110v is good enough, blah blah blah. It might work but if you can get something that will work better, believe me, you will apprecitate the difference.
Second, again, where will you be working? if your working outside in a frequently windy area, MIG wont work for you but flux core might. The other alternative is a stick welder but if your planning on fabricating and tackwelding frequently, you will want to get a wire feed welder.
For bang for the buck, I recommend a Hobart Handler 187. I used one to make everything that you can see on my truck except the bumpers. Everything that I have made except for my bumpers.
It comes with a cart and can be had for about 600-650. Add a tank and your just under $1000. Dont for get to get a package of spare tips and an extra spool of wire. I recommend using 0.035 size wire.