Glad you posted here as you'll get more responses than in the receiver & amp subforum. I'll copy what I posted over there:
What kind of alignment are they going to be in? That is a good price but you'll need a minidsp, as well for EQ. Rated 525 wpc @ 4 ohms means probably around 300-325 wpc real world, which would be considered underpowered, especially when you factor in EQ headroom.
A lot depends on the space and application. If you are modeling them in a program like WinISD, you can enter in watts & distance to give ballpark output to see if it meets your needs.
Just to give you an idea, I'm running my 2 sealed UM's with a Behringer NX3000D, which is rated at 1000 wpc @ 4 ohms, so real world probably around 600 wpc. That is underpowered too, but works for us in a smallish multi-use system. I haven't run into issues with music, but a few movies run harder than normal("Tenet" most notably)pushed it to the red.
Those few occasions are when it would be nice to have some more power on tap.