GM300 Radios have good shielding and rf bypassing. I use them they are cheap and I buy spares. And stay away from Hamtronics. I gave up that junk decades ago. Unless you have a service monitor and a spectrum analyzer you can't keep them stable. Modern commercial radios such as Kenwood TK-805D radios are cheap, plentiful and can be programmed from the front panel. The amateur rig of choice would be the Alinco DR-x35 series radios. They are midrange in price but interface well to the URI Since your new to Allstar/Asterisk buy a URI. Don't bother with trying to modify a USB sound FOB until you have some Allstar experience under your belt. I interfaced many radios. GM300 is hard to beat for the price. Observe you power settings and use fans on tx rigs