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.