So after playing around with the Astaro Gateway settings I have my P2P torrents working again. I will post my steps as when I searched the forum I found lots of threads on this topic and there didn't seem to be a lot of resolution.
1) Under Definitions/Services create a new service definition-
Name - Bittorrent
Type - TCP/UDP
Port - Select any unused port (select the same port in your bittorrent client)
2) Under Network Security/Nat/DNat
Name - Bittorrent
Traffic Source - Any
Traffic Service - Bittorrent (that you created in step 1)
Traffic Destination - External Wan
Nat mode - DNat
Destination - MyPC (the name of the computer you want to download the torrents to. I had created this in the definitions early - I tried using the internal Lan here but the setting would not take (further research is required).
Destination Service - Bittorrent
3) Under Network Security/Packet Filter
Source - Any
Service - Bittorrent
Destination - Internal
Action - allow
These settings have my P2P working again. I am not using a proxy/socks settings that other have talked about.
If you are having trouble getting your P2P working these settings worked for me. If you have some other settings particularly for the DNat that allows the destination to be set for the internal lan I would be interested in seeing them.