9mm versus 38 super for custom 1911 longslide.. twist...

So I've decided to have Jon build me a custom longslide 1911 wadcutter with rail. I wanted a longslide for my collection and don't have a nice 9mm yet, I'm open to 38 super as a possibility. Realistically it might not ever see real match use as I already have customs built by Jon in 38sp and 45 but might as well give it as good a shot as I can. Of those of you that have really gone for accuracy and shootability from a 9mm/38super what have been your results and observations? I'm open to either lead and/or JHP. Jon was thinking 1:10 may give best results with heavier bullets which might be less snappy.

The long slide should take some of the snap out of it.  If it were me and I was gonna use 147 grain bullets, I’d go with 38 Super and try and find a load that shoots well in the 690-790 fps range.

Personally would go for 9mm. A bit easier to get factory match grade ammo. Yes I could load either, but at the moment getting time at the reloading bench is a bit of a struggle.