Audio research 100.2 any good ?????

The 100.2 is great amp. I owned one and only moved to a bigger amp because of speakers that demanded more power. It will play just fine on you MA Silver 8's no problem and can reach a lot deeper than your current speakers. Parasound A21 is a nice amp but not as musical as the 100.2. NAD... really? I've owned NAD and very good for the money but we're not even in the same league here. The Parasound Halo Integrated is a good all around unit but it is not going to walk over a 100.2 with a great preamp. I had at the time a ModWright SWL 9.0 SE which was a great combination. Using your Marantz to drive the 100.2 will hold it back, so if that is your likely setup I'd consider an integrated as well but it's going to take something above the stuff noted above to outperform a 100.2. If you are thinking of a 100.2 you really need to mate it with a equally good preamp or you'll never hear how nice the 100.2 is. I know your speakers very well, so I can say with experience the 100.2 will likely have you moving up the Monitor Audio line so be aware of that. 

What integrated amps do you suggest that will match the 100.2 in musicality ? What preamps do you suggest ? 

The reason I was hoping to incorporate my Marantz is because I don't have a dedicated listening room and use h/t and music listening from the same system 

Yes NAD really!  Never said it was in the same league as the ARC!  I know; I use to own the 100.2.  Just helping the OP do some research and consider different avenues.  Don't forget, he doesn't have a preamp so buying a stellar amp may not make sense at this time.  I've heard NAD driving Vandersteen 2's and Treos.  You'd be shocked perhaps at the great sound being put out by them.  Wouldn't want the NAD long term with the Vandys, but it's a testament to their overachieving ability.  There is certainly nothing wrong with the Creek and Rega integrateds for a long term solution with the Monitor Audio speakers.   May also want to check out the new Belles Aria or Soloist 1.  By the way, I've owned all of these mentioned except for the Aria.  Good luck nesto179!

@nesto719....what kind of budget do you have in mind?  Do you plan on hanging onto the MA for awhile?  What percentage of music vs  movies (h/t)?  This will help.  Thanks.