Well, welcome to the posting side of AK to nearly ten month member (long time listener, first time caller).
The Powered Advent has two power amps built in one for each driver, 80 watts or so each and they will power you out of the room. They sound good but to me they can be overpowering compared to Stacked Advents (two per side) which is a great speaker system.
I don't know how hard it is to get the amps repaired. Some here may have addressed that aspect of ownership. The comments made reflect AK where vintage and cheap rule the day. There are some here that insist that this hobby pays them back and well it can so that is valid point and great that it was mentioned. Others are interested in enjoying the music/gear and let be like many hobbies, some times it costs money to play. It is a valid concern to evalute what an item is going to do when putting money into it whether it will be returned through use, flipping or just satisfaction of the owner knowing the unit was saved from the landfill.
Might as well dig to find the manuals, Service Manual especially and see if you can get them working properly and enjoy them while you search for more advents and deicde what to do with them.