I ordered one of the Model 1 Sales Colt Style slick side A3, like the one on the right...
https://www.model1sales.com/index.cfm?fuseaction=category.display&category_id=415&CFID=2637967&CFTOKEN=bf58f43284369483-35838659-C238-D336-B45AB9D42BFDF32B&jsessionid=A901A1A408A7721EAFA6F9573D061C31.cfusion
I gave them a couple extra bucks to ditch the big shell deflector and put a regular port cover on it. Mine ended up being a Keyhole Forge, same as the EF9 Lower. And the two were so snug I actually had to tap them together and apart for the first dozen or so times. Mine still mates up tight enough after about 2500-3000 rds that I haven't bothered to use the EF9 set screw.