OK, so I just this past Monday became a bike-commuter (yay!), having moved to a new house that's 6mi from work instead of 25mi. I'm using a seatstay-mounted Cateye blinkie, I'm happy with the brightness and battery life (I've had the thing for over a year and I'm still on the original pair of AAA!), but not so happy about the limited visibility between the seatbag above and the rack+bags below. Unfortunately, it only came with hardware for seatpost or seatstay mounting, and I really need to get it onto the back of my rack.

My rack has the metal tab sticking downwards with two holes spaced about 3/4" apart, which I assume is the standard light mount for bike racks.

Option 1 I'm seeing is a Planet Bike Rack Blinky 5, which I'm seeing for about $15 shipped from eBay. But I'm super super cheap, so I'm considering...

Option 2, which is to drill a hole into the plastic clip/sleeve I already have, and bolt it onto the rackmount (minus the screw-on stay-clamp). I'm just worried about whether I'll still be able to get the light's clip/flange in there. There wouldn't be room for a bolt head I'm sure, but a flat-top, bevel-sided machine screw, and a carefully-sized beveled hole, could be flush so the light would still fit in there. But that sounds like something I might screw up.

Option 3 is to just buy the Planet Bike rackmount hardware for about $5 shipped from eBay, which would securely attach to my rack; but would my Cateye clip into it? Are blinkie clips universal?

Option 4... who can link me the cheapest possible rack-mount blinkie? I'd want at least 3 LEDs with at least 3 modes: all-steady, all-blink, and at least one "chase" pattern. I'm not concerned with super-brightness (or variable-brightness)

thx in advance!