Black chrome is about the only option for a gloss finish.
Brownell's stainless steel bluing can be finished with a brilliant gloss polish under the bluing, but the look is more a dark gray then a blue-black.
There are problems with application and apparently durability, so many of the companies doing it have stopped offering it.
Black chrome is not very durable, only slightly more so then bright nickel.
APW-Cogan offers it, but only in a matte finish.
Coal Creek offers their QPQ Melonite which is a jet black. They used to say it could be done in a mirror polish.
http://www.coalcreekarmory.com/gunsmith-shop-prices/