Please help ...integrated amp under $1200

Welcome to the forum tboy. Undoubtedly you'll find this is a great place resource wise to pose audio related questions. 

The 1200 is a tough price point but for just a bit more ($1400?) perhaps a Musical Fidelity M3si would fit your needs. Among other niceties it has a asynchronous USB DAC built in (streams up to 24-bit/96kHz) so you could hook your computer right up to it and save some dollars elsewhere on a stand-alone DAC. Musical Fidelity typically gets a thumbs up on this site, but there are many here that know more than I and I'm sure will weigh in with their own recommendations.

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.