Which receiver would be the best choice?


Trying to power vintage Polk SDA 2's. Also have a pair of small Maggies that I'll use too. Both these speakers require a lot of power to perform properly I'm told. On a budget so can't get crazy. In my area there's 4 receivers for sale that may do the trick. They are:
Harmon Kardon HK670
Sansui 4000
Nad 7175PE
Lafayette 9090
Which receiver would be the best choice?
raisedonrock
I believe B&K is out of business. You might want to take that into consideration.
Thanks for all your input. I've looked at some new stuff and the Yamaha R-S500 and the Harmon Kardon HK 3490 look good. Which do you think is better of the 2 and would it be a better choice over the vintage stuff?
I'd go with the NAD, they tend to have robust amp sections. 2nd choice would be the Harman/Kardon...

-RW-