Ampeg svt 410hlf
 

I'm thinking of buying this cab to go along with my 7pro. According to musicians friend, the cab is rated at 500 watts rms with a peak of 1000 watts. Would this be a mismatch for the head?

Well, your head is
1000W @ 4 ohms
600W @ 8 ohms

And that cab is rated
500W RMS, 4 ohms

You can't really "mismatch" a cab to a head, per se...
However, you can smoke your cab.

It's fine to use that cab with your 7pro, but you need to be careful with the volume and turn down if you hear the cab struggling.

+1 first off, forget wattage ratings. Just use common sense, and your ears. Yes, it's possible to toast that cab with the 7Pro, but that's no reason not to pair them. Just be sensible, and cautious, especially with any added low end. THAT will hurt the cab quicker than anything.

Great match. I would go for it. I've owned that same cab and pushed 600 watts with no struggles at all. Listen to the cab, and don't overdue it.