for the coheed & cambria kinda tone? but can also go uber high gain muse? im kinda leaning towards a metal muff but im not sure
Matt from Muse uses his beastly Diezel amps for distortion tones. If you fancy a new amp, they're bloody expensive. He also uses a ZVex Fuzz factory for his fuzzy stuff, which is also pretty expensive.

Based on the price range of the metal muff, I'd probably say something like the Hardwire Metal Distortion or one of the MXR Distortions.

If you can stretch your budget out to 150 bucks, go for the Zvex Distortron.