The USAF has been about “boom and zoom” since well.. there has been a USAF.
COIN aircraft are low cost low impact and not beloved by the USAF by and large.
A modern choice could be The T6 Texan-2 stable mate the AT-6 Wolverine. Which would make learning curve nearly flat and support fairly easy compared to a new or very old aircraft.
http://defense.txtav.com/en/at-6
Sky Raiders use pretty much the same engine as the B-29 (FIFI is using Sky Raider engines now) and are not exactly low cost low maintenance.
All true - I posted Skyraiders because another poster commented that CAS birds are getting lighter and smaller - A-1 max takeoff 25,000 lb vs 6,500 lb for the AT-6 with less than half as many hardpoints.