Howdy cook. Not sure if you got the link right. That rig isn't a miller, it's a Lincoln Electric. It looks like that weld-pac 180hd goes for less than $700 brand new from homedepot. You should be able to find a better welder for around $800 used.
Hmm. There are a lot of folks on this site that are experienced with various welding machines. I looked for something that used shield gas, could put out 200 amps and had a good duty cycle (better than 50%). Miller makes a good welder. Your power availability may determine your choice as well. I had to get a dedicated 220v circuit installed for my machine (millermatic 200). If you only have 120v, flux core might be your route. You should be able to weld 1/4" in a single pass with 180amps. If you end up getting a smaller welder you'll just have to weld more passes. That's my 2 cents