A follow up, I bought a couple of the flat path markers off amazon, they're definitely bright enough to see from over a mile, closer to 2 if I know where to look. They were only $10 each and I think I'll go with them for now. Still might put a brighter flashing unit on the grain leg so I can see the field location from farther out and off axis, but the runway itself is pretty easy to line up on now from either end. Thanks for the tips.

Patrick