ProTune makes a gear indicator with a redline indicator. It comes with a wiring harness that plug directly into the OEM wiring.
I tested it last weekend on our 1098 project:
(it is the little thing on the left)
I don't think the product has made it to our website yet, but Nick can tell you more about it. He is organizing a group buy becuase the minimum buy was high.
I'm not sure if it has the SS plugs- buit it should not be too different than the 1098 and SF.