Burris makes a long eye relief 3-12x handgun scope. https://www.burrisoptics.com/scopes/...cope-3-12x32mm
According to the specs the eye relief is 10 - 19 in. at low, 10-12.5 in. at high. This being said a 24x with 16-18" of eye relief like you're looking for sounds either very very expensive, non existent or both.
I don't own one of their handgun scopes but swear by their rifle scopes.
I shoot a 2X on my 8" .357 revolver because any more magnification and the recticle bounces around too much while trying to get steady while hunting. That and a .357 handgun isn't exactly my first choice past 50 yards with maybe 100 yards for bad case of big buck fever and any further than that just for fun.