Yeah, I checked under Probotector and Gryzor. I was actually hoping I would find it under Gryzor since I believe that version has some extra stuff added like cut scenes and more background animation, but alas it wasn't there under that name either
Contra ReBirth is good. Think of it as being more along the lines of Contra III and Contra Hard Corps though. Gradius ReBirth is cool as well. Not the best in the series, but it's styled like the 16-bit era of games and is still good. My only real complaint with it is that it makes you play through it twice in order to "officially" beat the game. Weird for a Gradius game..