First, on red dots: +1 for Aimpoint (if you have the money). And don't be tempted to get the TruGlow 2X red dot -- I did, and it's a total waste of time/money.
I built a version of a scout rifle, and because the mounting point of the scope was restricted, I ended out needing a scope with about 12" of eye relief. I wanted more than 2X or 4X magnification, so the dedicated Scout Scopes (Leupold and Burris) wouldn't do it for me. Bushnell has an "extended" eye relief scope, but it only goes to about 6" (IIRC). So, the first thing I suggest you do is actually measure what you need. On the other end of the scale, most handgun scopes have 16"-18" of eye relief. In the end I found a Burris Handgun scope that has an adjustable range of 11"-18" of eye relief - and it's a 2-7X variable, so that did it for me.