They may be all in, and I believe Firebird is now even making one from scratch vs modifying the Akdal, but just like 667 I've never seen one at an actual 3gun match.
We've been to a few.
All the open shooters I've spoken to say they kick like a mule, and any early adopters have given up on them.
They stick to the Saiga or run an xrail on their M2.
Even the Saiga guys I know are looking to get rid of them and move to the Xrail, due to the Voodoo required to keep a Saiga running with any sort of reliability.
Sorry for the thread drift JACKSONLEWISOFCANADA.
Before you buy, see if there is any way to try a few of everything out by going to a few matches or hitting the range.
Seeing as cost is a factor, I would start with what you have even if it isn't as competitive as the "best" equipment out there.
Once you get a feel for what you actually need, you will be in a better position to actually buy and save money vs experimenting with equipment that you will end up ditching.
An AR15 is a very easy platform to learn and is easy to customize to your needs down the road (its like lego)
Use your Sig for the pistol until you feel you need something different
For shotgun, if you are going to go pump, I would get a Benelli Nova. You can probably find a used one for $400 and a new one for maybe $100-150 more, and it is a quality gun.
Huge loading port and simple controls.
For a semi, the Benellis are the most widely used for a reason, but cost is a factor there.
The Versamax is a decent gun, and the Stoeger M3000/M3500 has been proving itself as a good "entry level" gun in the US.
The best advice I can give though, go to a few matches and see what people are running, and ask questions.
Shooters are typically attention whores and if you admire their equipment, they will more than gladly tell you more than you wanted to know about it.