I’d at least get a RadioLink RC6GS for a Tx. Not sure about that GT3B. I wouldn’t trust my speed run cars to that, just my opinion. As far as batteries go, what’s your budget? If you are just getting into speed running then some of the CNHL 90c or the G+ 70c will be fine and cheap. No reason to spend $350 on the top of the line Onyx or SMC SRD packs at the beginning stage of speed running.bumping this, I have a flysky GT3B, would just a range extender be sufficient? also what is everyone running for batteries? My QS8 connectors showed up today.