Greetings Jason:
Just guesstimating from your photo, that little HF mill will do what you need. Check out
www.littlemachineshop.com for a bunch of info about those mills. They usually need complete disassembly and cleanup to remove the shipping preservative grease, dirt, and grit from manufacturing. Check out the work envelope, that is, the size of work that the mill can handle. Your work will have to fit in that space. The mills will take light passes in aluminum and plastic, but lack rigidity, spindle speed range, and power of more massive mills that can handle steels. Try to examine the actual machine you will buy. There is a lot of variability in quality and accuracy among these machines, so in general, they are considered a machine tool 'kit'. If you want higher quality, look at Sherline, Taig, and several others. Consider that tooling (vices, setup, measuring, cutting) will set you back several times the amount you spend on the mill. Look for an adult extension school where you can take a metalworking class if available. Sometimes have some big nice machines to work with for not a whole lot of tuition, and usually an experienced machinist instructor. That will give you some machine time to see what your needs are. There are also many hobby metalworking clubs that make everything from steam engines, model rockets, trains, etc. Maybe go to one of their meetings if there's one nearby, state your goals, and scrounge some invites from members to see their shop setups. Take a look at bigger machines that even used, might pay same for a whole lot more capability that retains enough accuracy to meet your needs. It doesn't take much to cumulatively spend as much fixing up a new chinese machine to equal the acquisition of a used but much higher quality machine. Anyway, there's some random thoughts, good luck with your business.
Regards, Jim Brown