Podcast Search Engine and Synchronization Software

I am looking for the most efficient software that not only catches podcasts but can also search for them and sync to them. So I am looking for a single tool that will totally manage podcast feeds but won't do anything more then that. I have zen micro player.

So far I found:
Doppler
Zencast

So the question is: which is better, i.e. more efficient at tasks such:

-finding a podcast
-subscribing to a podcast
-managing podcast feeds
-syncing with PC
-syncing with mp3 player

Please tell me if you know other free applications that can do that, too.