Go with Naim. I have owned older Arcams and listened to the Naim XS. If you want crisp sound, fast transients, and good pace and timing, the Naim will give you that. There are many users who love the the musicality of Arcams. The Arcams will be soft-sounding in comparison with reduced macrodynamics. I never liked the Arcam sound, just not to my taste but they can sound good in the right system. No experience with Linn.
For Proac 1sc you might want to consider tubes. Read that the 1sc sounds fabulous with tubes.