I need to place my Time Capsule a fair distance from my ADSL router, and cannot easily run an Ethernet cable between the two. Can I use a pair of Powerline ethernet adaptors to make the connection? If so, any advice as to recommended make/model.
Yes. From a network point of view, power line communication devices act like a bridge (or a switch, if they support more than 2 ends). That means they should act completely transparent (not accounting for transmission errors or other problems).