The light can only take 3 wire ignitors due to it not having any direct neutral wire on the ballast.
Actually, the 2 wire ignitors that I linked to you on eBay can actually work on high pressure sodium ballasts normally designed for 3 wire ignitors. In the installation instructions of these particular ignitors, you cap off the X3 or blue tap that you see on the ballast. In that case, the ignitor is simply connected in parallel with the lamp. I can draw you some wiring diagrams that show how this 2 wire ignitor is installed vs a normal 3 wire ignitor on the ballast that you have in your fixture. In your case, the ballast in your fixture is a simple reactor/choke ballast wired in series with the lamp. The top diagram represents how to wire the 2 wire ignitor to your fixture and the bottom diagram represents how a normal 3 wire ignitor is wired to your fixture.