OK, I'm a wuss and am going to have my local shop tackle this carb mod. I trust them and they have always done me right in the past. I can also have them double check the SuperTrapp install.

They recommended a DynoJet Stage 2 or 3 kit. What's the difference?

I've gone through all the posts when searching for Dynojet but am still not sure.

Since I was considering the DJ kit I looked at it, too. A question I have for those in the know on the DJ, Since it requires changiung jets to tune the carb to the Trapp, how much easier is it to tune the carb to the Trapp with the DJ kit?

Since it will be shop time, possibly the cost of the DJ kit will be saved in time required for the shop to change jets at a quadrillion $$$ per hour? The thing to consider is time required for each method & compare the cost of the labor time to the cost of the DJ kit. If it's even close, I would go with the DJ kit, so if Hunnus decides to change the number of Trappo baffles he won't have to buy jets to tune the carb.
I hope the shop will let ya watch some of the jet installation. They probably won't cuz they know if you saw how easy it is you would take it home & finish it yourself.
Maybe an estimate on labor before you can decide if you want the dj kit? Pop the carb off & I will replace the white spacer with a 1/2 washer & rejet it. You pay the freight & I'll do it for $20.00 I live in Longview, UPS can get it to me in a 2 days & I can do it & you will have it back right quick.
Then you can add baffles to the Trapp to tune it. You want a 155  main & a 55 pilot?Send jets & carb, I will do the rest. I will send the spacer back w/ the carb, along with the original jets. You could then adjust the idle mix & ride on!I am sure you will save a stack O cash that way.

I used the Dynojet DJ144 main jet. It worked well.
If you have a more agressive intent use the DJ145.
Since you're using the SuperTrapp, you can go to 10-15 discs with the DJ144. You need to experiment with the SuperTrapp until you have the right mixture. Look for minimum black soot.

I don't know what the stage 2 and 3 kits are.

You need to be more involved in this operation and define what you want.

BTW. The Dynojet Kit eliminates all the crap with the white spacer. You use the stock spacer with a new needle with multiple groves. Just follow their instructions.