BG
There are many people and business running Avid cnc.
However a heavy welded frame is always better than an extrusion frame (The same reason Machinist love the old heavy cast iron lathes and mills, they are heavy and have lower vibrations)...at first I wanted to build my own frame with Avid components.
But since I had much to learn I bought just about everything they were selling. I do not need production speeds and also since I have 2 z axis motors I do run it a bit slower.
Future plan is to have a dedicated Plasma cnc Avid as well so I can use the components that I have already. and now that I know more I can make a welded frame.
It's better to have the machine first to make parts for your next machine :).
for the ATC i got into contact with the company they responded quicky and got the pricing...but it is not a priority for me.
I found out about Phantom after I bought my machine,,,the machine looks good...however I do not like the cabinet style controllers (personal choice). monitor when it breaks I just go out and buy a new one. If my pc controller break I just get a new cheap one. locally available.
The way the other cnc have their lathes installed on the side got me interested to do mine the same way.
Since you are wanting to do intricate stuff take a look at these as well
https://www.camaster.com/machine-options/
https://www.youtube.com/watch?v=67LekRPkhNM
I noticed that Cammaster use yaskawa electronics...my experience with yaskawa vfd drives they are much more reliable than ABB, GE, Mitsubishi and Allen Bradley drives.
Avid uses Delta drives I still had no problems and if something happens I can get one from amazon or ebay.
Again imo support and parts availability is important when buying expensive machines.
if it is for business I would buy a turnkey machine ready to go.....mine is more for hobbies as I always making stuff and modular was the main selling point for me.
On the software side maybe check with Deskproto if they can do what you need.I only use vcarve. if you are going to do signs you most likely to end up with Vectric anyways.
I was always interested in 3d modeling tried many times and gave up when I found Moi3d I was able to draw something the same day. So I bought it and use it almost dialy for just about everything 3d printing, wood working design, metal designs etc. You can always use it in combination with other programs Rocket3f, blender, 3d coat etc. which is what I am planning to do.