My everyday carry set up is a glock 26 in a stealth gear onyx (I absolutely love this holster!). However this doesn't work for when I am running and / or not in jeans.

I just purchased a ruger lcp ii to fit this niche.

I am looking for a good quality thigh holster to go with this gun that will allow me to wear dresses and skirts and carry that will also function as a way to carry while I run.

Any ideas will be appreciated, thanks!

I don't think a thigh holster would be secure. I've carried in a belly band for 12+ years. Skirts, skimpy workout shorts, etc. I like to run around the woods and walk the dog in a fanny pack sometimes too, but the belly band works for me whether I'm carrying a G19 or P3AT.