There is now the Ebay link along with Mixcloud and Soundcloud.
The Mixcloud and Soundcloud links just use the full web addresses and should look like the below:
Mixcloud:
[mixcloud][/mixcloud]
Soundcloud:
[soundcloud][/soundcloud]
Ebay just uses the item number i.e [ebay] 4644444 [/ebay]:
Jay X-treme rig
[ebay]291120418489[/ebay]
Enjoy!