Your Garage is probably bigger than my back room. It's about as wide as one of those cheap metal sheds although I have more headroom and it's twice as long. I have a Zx45 in there, although in converting it to CNC I am going to have to flip it sideways to maintain some clearance for the X axis. God help me if I move.. anyways the 45 series clones are the largest benchtop you can get. if you plan on working steel with any sort of precision and speed I would recommend that it be the smallest mill you consider. it is best to go as large as possible. a Used Bridgeport can be had for the same price as a new 45 and is much more capable.
If the 45 is what you have to consider, stick with Precision Mathews(PM) or consider the Charter Oak mills (A little spendier but much better quality).
If the 45 is what you have to consider, stick with Precision Mathews(PM) or consider the Charter Oak mills (A little spendier but much better quality).