I've powered my Sttafs with many different amps and they all worked well. You don't indicate a budget range, but staying in the neighborhood of the NAD there are a number of options. I like B&K amps - and if you want to power 2 sets of speakers a multichannel amp is an option. One of these would be quite nice. (I don't know the seller and have no interest in the sale).
Other options - Musical Fidelity A3cr, PS Audio HCA-2.
A Dared SL2000a preamp is one tube preamp worth considering in the presumed budget range, but only has 2 inputs. are great.Other Tube preamps I can think of will run $700+, but in the $700-1000 range there are probably some great choices (eg, TAD 150sig if you can find one). In Solid State - staying with B&K and PT-3 or PT-5 are great for the money.
Other options - Musical Fidelity A3cr, PS Audio HCA-2.
A Dared SL2000a preamp is one tube preamp worth considering in the presumed budget range, but only has 2 inputs. are great.Other Tube preamps I can think of will run $700+, but in the $700-1000 range there are probably some great choices (eg, TAD 150sig if you can find one). In Solid State - staying with B&K and PT-3 or PT-5 are great for the money.