I think I posted in here already - but most for your money on a decent impact right now is that Ryobi promo kit.. it's priced cheaper than the bare tool itself, and come with a charger and 4.0 battery. The battery alone is $79 retail, and the entire kit is still priced at $99, in store only if you can find one, and you'd better hurry up cause these are not normally stocked items.
To be clear - the Ryobi is advertised as having a pin lock. However it is not a "typical" pin lock design, meaning you DONT need a tool to remove the socket like you would on a real pin detent. It's "modified" so to speak, so it has better retention than a ball type, but doesn't need a tool like a real pin detent.
At $99 - you WILL NOT find something as good, for that price. It's even cheaper than hf's newest 1/2" impact sold under the Bauer line. For what you describe, this would be plenty good for your needs..
That said - if racing is important - and you need something better - then take your pick at the better brands, but your cost will be about $250 for a single battery impact from say Milwaukee.. better impact? By far.. stronger? God yes.. but for $100 the Ryobi will do the same thing. Wheels constantly being changed dont need an impact with 700 ftlbs plus..
Don't get an impact driver for this.. will they work- yes , but the wrench is what you want, and right now that kit is cheaper than a bare tool impact driver anyway..