Frankly, I'm not sure that a binary would be of much interest to Developers, your target audience. I know that if source is available for anything, we don't bother with a binary - we rebuild it as required.
Indeed, this building step provides a valuable insight for us into how the project is structured and also, what the code looks like. If we're going to use anyone else's work, we tend to take a hard look at it first - unless we paid for it, in which case we take an even harder look! (And then complain loudly if things don't work as advertised :-) )
On the installer issue, generally, the standard directories used by others do not always fit our own directory structures. So headers and the like end up in places we'd prefer them not to be.
So, if I were you, I'd save myself the work of an Installer, and put the extra effort into producing really elegant Makefiles and well-thought through documentation. Much more valuable in the long run.
