Speed Shooter's Intl has the Brazos bald unique and classic slides ( https://speedshooter.com/product-category/slides/ ).
Jem is really good but not sure on what they have in stock ( https://www.jemguns.com/Custom-Slides_c_15.html )
Tripp is also making slides, Shooter's Connection has a classic bald slide ( https://www.shootersconnectionstore.com/9mm38-Slides-C938.aspx )
Another option would be Remsport: https://www.tr-enabling.com/product-p/sl-g-c-9-000-00-00.htm
Atlas started selling slides but they are out of 9mm bald slides but you might want to call them to check availability ( https://atlasgunworks.com/product-category/slides )
For hybrid barrels, have you looked at SV/Infinity ( https://sviguns.com )? You can order the slide cut for their ribbed barrels (it's a $73.12 option). I ordered a hybrid barrel and spec'd out a slide from them on Sept 5th and it's being delivered on Monday. Keep in mind that the new SV/Infinity slides have a proprietary breechface with integrated extractor now.
Hope this helps.
Hope this helps.