2000 Chevy Silverado Throttle Body

Engine Performance problem
2000 Chevy Silverado V8 Four Wheel Drive Manual 98k miles

I've seen the throttle body spacers advertised to increase horsepower at mid and low range. I am wondering if there's an aftermarket throttle body assembly that provides additional performance gains. If there is, I'd install both at the same time rather than do the spacer and go back later to replace the throttle body. Every website I look, the throttle body assembly doesn't advertise a gain - just a replacement. Thanks for your help!