Yep! I sell the premades here: SelfPubBookCovers: One-of-a-kind premade book covers where Authors can instantly customize and download their covers, and where Artists can post a cover and name their own price. And this is my main art gallery site, which shows commissioned covers and past sales: Book Covers by Viergacht on DeviantArt
I've either used Damonza or made my own. I made two of the covers in my signature myself (admittedly one of the two I made is unfinished). The rest are Damonza. They aren't the cheapest shop in town, but they know how to build a book cover that inspires purchases.
On a related topic (an perhaps this is discussed elsewhere?) but I'm interested in getting some character art for inspiration and promotional purposes. Has anyone had experiences in commissioning art (other than cover art) for their litRPG stories? I have used Fiverr in the past for projects (logo design) - but this is a pretty niche job. There are a couple of people offering D+D character sketches, which may be my best bet. Suggestions??