I can recommend Hugo Paris at Tiny Crush Mixing for the mixing part, and Nathan Moody at Obsidian for mastering.
They are both stellar, neither are cheap. Like, not even near cheap. However, they're both worth every penny.
If I do another all-the-way album, I may find someone local to me for mixing, but I will definitely go back to Nathan for mastering. If I had label backing I'd request Hugo again in a heart beat.
One of the things to keep in mind is what you need. Are you looking for MIXing, or mixing? If you're pretty happy with how things are sounding and just need to make sure levels, EQ, etc, are good to go for mastering, I don't think you'd want to go with someone like Hugo. If you want a deep dive though, he's the kind of mix engineer you want.
Nathan's my guy for mastering, period.
There are many, many, MANY others out there though.
Inscrumental music for prickly pears.