I'm sorry to say this but you get what you pay for with some things. The $25 orbital won't do squat except make applying a wax easier but even then it's not that great. The DuPont spray wax is probably one of the worst detailing products I've ever used. It wax impossible to apply thinly and even more impossible to remove. I used it twice and thankfully it fell and exploded on the garage floor. I haven't used Simonize so no comment there. The MF towels you have now are OK but I'd never let them touch my paint. You'd know what I mean if you ever buy a quality MF towel. As for the Turtle Wax Liquid Clay, it's actually a paint cleaner and doesn't act like a real clay bar. Also, if the tire dressing you have is see through, it is probably silicone based and that really isn't good for tires, over time it dries them out and cracks them.... If you want the results, it's going to cost a little money. As you probably already know, here is the process of an exterior detail, minus wheel and tire work and windows:
Wash
Clay
Polish
Sealant or Wax
I'm not sure what condition your vehicles are in at this point in time but it's going to be a lot of work to polish the swirls and marring out by hand... A lot of people have the PC7424 and for good reason, it's a great entry level polisher that'll yeild professional results. I can't name off any polishes that work by hand because I don't use them ... scratch X would work but that was designed for small areas, so if you use that be sure to remember that. So unless you are willing to buy a machine, I can't help on the polishes (BTW all buffers are on sale until Monday

). Having a machine is a definite if you are even thinking about going into business.
A great OTC wax would be Meguiar's #26 liquid or paste. But again, there are many other high(er) quality waxes available on Autogeek that are easy to use and look great. Do what you can on your budget now but save up some $$ to place an order ith AG, you won't be disappointed. If you are willing to buy a PC or UDM with necessary pads, I'm sure a lot more people would be able to point you in the right direction concerning polishes and waxes.