Does either printer have an ethernet port? Otherwise I don't know how a powerline adapter will do you any good.
I've been happy with my linksys WPS54G, although I probably wouldn't use it with a multi-function printer. If you want a multifunction network printer, I'd suggest buying with with a built-in print server).
Don't buy this. Mine was freeking HARD to install, largely because Verizon FiOS network config conflicted with the IP ranges that came with the Linksys router. I had to grab an old router to force the print server to a different IP address and password and all. I consider myself computer savy, and that took me some time to figure out. Then to top it off, once installed, don't ever plan on printing photos if you'd like to hang them before you pass away. My printer went from printing 1 page of text every 5 seconds to every 30 seconds. I now have a really long USB cable instead and my 100$ investment sits next to the printer unconnected.
No firmware has been updated either, which is apparently part of my problem from my research. Your experience may be different, but from the searches I've done, I've found very little people who were ever happy with this. I question if they really ever had a fast printer to begin with personally.
-csa