Hi there!
You can find all the info on my website in regards to commisions (penzilladesign.com/commissions) and prices (penzilladesign.com/prices), but at the moment I'm not taking on any new commissions, as I have several larger projects going on that takes priority.
Do however check out this pack: https://penzilla.itch.io/huge-hellscape-platformer-tileset , it's a pack that will work with the assets in this one, and it already contains some enemies/bosses :)