There are several shops out there that offer custom gun coatings. You can strip it and Gun Kote it yourself for the price of a can of the stuff and some over time. It's not the best choice, but it's cost effective.
is one of the leaders in this category and I have my 1911 .460 Rowland build off pistol with them currently. I have seen their work and been very impressed.
is now offering two types of custom finishes. Perma Kote, which came on my T3 seems to be very durable and I haven't had any problems with it in over a year plus of CCW. They are also offering a finish called Diamond Black, or Black Diamond, something like that, that actually penetrates 2 mils into the steel and is guaranteed for life.
is a company that has been garnering interest lately. I don't know anything about them, but I have heard their names in a few conversations.
I imagine that Dave Lauck and Les Baer and custom gun guys like that probably have some specific coating that is proprietary to them only and will probably cost you a second mortage.
Take a look at those and see what you think...