Need a quality vest to hold ar/ak mags and sidearm any suggestions

So you probably don't need a plate carrier type vest. I know NOMAD is selling a load bering type vest in the FS - Misc area. Adding a couple mag pouches and a pistol pouch or using a g-code holster might be one solution?

Galaxy S3 via tapatalk v4 Beta
 
Tactical Tailor has a nice set up that you can wear like a vest set up for your type of mags and you can adjust and play with it to change it to what you need.
 
I had one of the chest rigs before the product was taken to Eagle. As SKD sells it, it is a good product for sure. I dont care for the weight out front, items stacked onto the front of the rifle mags. I use one mag pouch as open top, and prefer to have the rest under good, secure flaps.

For the OP, Ive never tried running my tractor with a chest rig on. Have to assume your use would be no different than "mounted" operations of the non-farm type ;-) I think in the long run, you will like the less is more approach. Wearing all the cool guy stuff gets pretty boring when there is nobody around to shoot at.......