I have used a Hoppes gun blue kit in the past but can no longer find them. they gave a nice rust blue finish when used with hot water.
Here is the one I prefer now, Brownells classic rust blue http://www.brownells.com/aspx/Search...aspx?pid=22820
With proper metal prep and taking your time a nice rust blue finish is absolutely stunning and much deeper than the typical cold blues.
Good luck with which ever route you take.