Never heard the PS-6a but .... I picked up a pair of Design Acoustics PS-9 speakers and replaced the tweeters with SEAS. These speakers have the down-firing bass woofer. They have been mated with a Sherwood 7100A receiver from the 70's. Result: wonderful sound with suprisingly decent bass response. I would not hesistate to grab the PS-9 or PS-10 speakers and do the mods.
