72 CD Boards????

Hi,

I have a chance of getting a 72 and have noticed from different threads that you can get different cd boards as well as different phono boards.

Which are the best CD boards and should I worry before I buy it?

It's from a dealer so I can most probably have a listen in the shop.

Also, is it going to be a big difference over my 92(nait conv)? My sys/sistem: marantz cd 63-ki sig, 140, proac tablette 50 sigs.

I intend to change my proacs for intro2s, I have already had a listen to the intros but was a little overwhelmed by the bass in my room. Will the 72 give me more control over it or is it just down to speaker positioning?

Thanks

Tony