While it's not the cheapest option, and you might have to wait on the waitlist, HK does sell the optics-ready VP9 slide in their webstore:
https://us.hkwebshop.com/hkstorefron...hts/p/51001080
Steve @
Colorado Holster makes really nice Kydex OWB and IWB holsters for quite a few pistols including the VP9. He made me an OWB for a VP9 w/ threaded barrel plus TLR1 a while back and it's as nice as any Phantom that Raven ever made, and I have a box full of Phantoms. Plus he's a super nice guy and his prices and lead times are very reasonable.