Take a peek at Notepad++. I feel that this is the best editor for coding, hands down.
NPP has the functionality you desire, as well as syntax folding, syntax highlighting, etc.
It is an open source project too, so all the better. Furthermore, being oss, it has quite a number of useful 3rd party developed plugins. Like SciTE, it too is based on the Scintilla - a nice and very powerful editor framework.
Take a peek at it
here, or you can visit the SourceForge project homepage
here. I think it has been in the top 5 for
most Active SourceForge projects for quite a while.
The tool is still being actively developed, is very stable, and quickly fixed when a bug does surface.
I am actually coding up an AHK based ARMbasic IDE with NPP being the editing component, and AHK fulfilling the balance of the IDE functionality.
Another alternative is Crimson Editor. It is a nice stable tool too, but not nearly as aggressively developed, and not as feature-ful...
Good luck!
-t