Please help ...integrated amp under $1200

In addition to the NAD you suggest there are several nice solid state integrated amps for sale on Agon now at or below that price point including: Creek Discovery 50A, Naim NAIT 5i, Hegel H70, Vincent SV-256 mk, and Primare I22. Depending on your taste, some nice choices. I have heard all but the Hegel and like them, but think I would look hard at the Primare as it would sound good with MA Silvers.

There is a Croft Integrated on the 'gon for $1100.

Decide on the speakers first and then find an amp to properly drive them. 

This should be the primary consideration in choosing an amp.  But you have to know the requirements of the speakers first.  The rest, like a DAC or a phono stage are just features.

As paraneer suggests, pick your speakers first. The MA Sliver 10 is a great speaker but I would want at least 100 strong watts to drive them properly. Not just for satisfying volume levels but for good control of the speaker so you can enjoy all they can do.

A good amp that you could get for close to $1200 would be the NAD C375BEE.

Decide on the speakers first and then find an amp to properly drive them.

Agree! If you do this you will be reducing your risk of wasting lots of money. Decide what type of speakers float your boat first (sealed box, ported box, panel, open baffle, horn, etc.), then select your favorite of these. Only then shop for an amp to match what your speakers require. Of course, you should also check out powered and active speakers as well, thus saving you the trouble of purchasing an amp.