Hey, Bob, Welcome to CncZone, great to have you here.
Torchmate uses Flashcutcnc's software and drivers, so if you want a little more information on them, that would be what you need to look up.
I tried the Flashcut demo (1.6, I think) at one time,in an effort to generate Gcode (just to see how it worked),but have not used the newer software but I have hear that it is fairly easy to use. It works very much like most other CNC machines, in that a CAD program is used to create part or drawing, and then a CAM program generates Gcode that the machine understands.
It will probably have the same amount of learning curve as any other CNC plasma setup, you have to tinker with it to really learn it. As much as any company would love to have you believe, there is very rarely a "click,click, cut" software out there. That is not to say it will be hard, at least depending on how computer savvy you are.
Again, I don't use Flashcuts' latest and greatest, so it would be better for someone who uses it a lot to give you a more in-depth explanantion.
As far as ATHC, I would recommend them, especially when it comes to 16 gauge. I don't know much about their ATHC, but for reference I suggest you look at www.candcnc.com for a good comparison chart of a few ATHC's. Now, most on that list are not compatible with Flashcut, but it is good research.
For cutting jobs, everyone has a different method.
If it is a friend or relative, I will only charge for metal and consumable cost (and if the metal is a small piece I can get "left over" from another job, then
it's free). Custom or repetitive parts are generally figured up based on the amount of cut time, cost of material, cost of consumables.
I go by a 40 dollar an hour rate for designing parts. I hate staring at a screen and cleaning up someones hand drawn work to make a cut file, so sometimes, I charge more for more intricate work.
The kits look nice, but which is going to be the better deal for YOU?
If you get a kit, you are paying the markup on the 80/20 extrusion, the cost of shipping, etc. BUT, you will have something you can snap together in a matter of a couple hours.
If you build the table, you pay no shipping, no high aluminum costs, no markup, etc. BUT, you will then have to buy 300-500 bucks worth of metal, and design, cut, weld, grind, bolt, etc for a couple or three days until you have your table.
How much is your time worth? If this is a thing you can put off till the weekend, then build one. If you need to ship this thing in and snap it together, and be up and cutting in a day or two, buy the table.
If you can weld, fabricate, and have a good work area, then you can probably build a table, just take your time and get it right the first time.
The extruded aluminum they use is typically strong enough, and it looks really nice and professional. The downside is, as you have noticed, the cost.
Shipping alone for such a bulky item will be a costly item, plus aluminum is VERY expensive.
I hope this helps, sorry for the long post.