You could try a One For All/Radio Shack remote and see if the 0158/0159 device codes work it. Sony uses some very strange IR protocols for some of their amps & receivers which are universally difficult to program using universal remotes (including the Sony universals, go figure!)
Some Philips Pronto users have been able, after much trickery, to get their Pronto's to learn the difficult Sony signals, and have created files for them which you can download, so if you don't mind using a touch-screen remote, maybe you should consider a Pronto.
Rob.
http://www.hifi-remote.com/