Full race:

• HW XR10 Pro ESC
• Trinity Slot Machine or Fantom Icon or R1 Wurks motors (they each have "team" editions as options too)
• Lots of good servo options here but I see most people run Protek 160TBLs
• Protek LCG 4800 is my go-to battery, but lots of brands make a similar version
• Sanwa M17 radio

Competitive - you're saving few bucks but are unlikely to hold you back at all on the track:

• HW xr10 stock spec (saves you $50+ over the Pro with minimal difference in performance and you gain some weight savings
• Non-team versions of the motors above
• Protek 160T or a $100ish savox
• Still recommend the Protek LCG 4800
• Agree with the poster above, Sanwa MT-5 or Futaba 4PM, but you could also check out the Flysky

I also recommend talking to the guys at the shop at the track you'll be racing at to get a gauge on their support for these products. I don't expect there to be a lot of support issues with these brands but always worth checking. For example, if they don't carry Protek servo gear kits, you'll be SOL if your Protek servo strips a gear while racing. I also try to spend as much of my money at my local shop to help keep the lights on.