I'm not well-versed in FR-equipped guitars so I can't say much about that.....
Basically you have to ask yourself, whether you just want a clean channel on the amp to function as an empty canvas, using your effects primarily for drive, or you want to use the onboard distortion as a base to add on to.
Personally, I own the Cube 30, and from my experience, it's more of a jack-of-all-trades. The main feature that would induce people to buy it would be the number of amp models and provision of basic effects, making it quite a versatile unit which can deliver a number of tones decently. Certainly, the Cube can handle heavier sounds, it has a Mesa Rectifier model as well as a few other high gain amp models.
Judging from your music, you'd probably want a high gain distortion unit. Again I'm not a owner or user of any such pedals so I think it's best left to those who are more familiar with these effects. Several suggestions have been made earlier in the thread and I'd recommend that you try out the different options before you decide on your purchase.