I see there are a few company's that make the big jigs that go inside the barrel slot to smash the rivets with a press. I have built about 8 AK's using the bolt cutter style smasher, I want to buy something a little better to use. Thanks in advance for any advice.

AK-builder has the best rivet jig.

+100

Another +1 to AKB. I've had their rivet tool for a few years now. It works perfectly for all the different builds I did. Very solid, has excellent reach and well made.

i just bought the short rivet jig from gunthings.com. way much nicer than the POS i homemade years ago out of junk iron when kits were cheap and could afford to mess them up. after using it on a $400 polish kit, it's worth every penny!!

AK Builder does make a good riveting jig, but a big price tag doesn't make it the best.
My first build I made my own out of a 3/4" grade 8 bolt like this, and believe it or not it worked great.
It works for all the rivets on the front trunnion of the Romy G.
To do the swell neck rivets you need a 1/4" ball brearing.
Just set the BB in the cup of the bucking bar where the rivet is, locate the rivet hole over the BB and press inside the trunnion with the bolt riveter until you get the crimp you need.

Please excuse my makeshift drawing, I would have taking pictures but I gave the set-up to a friend when I up graded.
I used a 5" or 6" bolt & cut the threaded end off, then gound the end of the shaft into shape, it is best if you keep the bolt as short as possible.

Thats an interesting idea. I may have to make one.