Anyone dealt with WCF and clustering?

This is rather tricky.

Ive been spending the past 4 days endlessly to create a virtual environment for clustering. 2 Nodes are clustered.

I want to be able to send a message from a computer to another computer via MSMQ.
So learning about things, I made an MSMQ clustered queue.
When the sender (CompA) sends a message to the clustered queue, in theory, it will keep it there and WCF service would pick it up and process it regardless of NodeA or B is down as long as one node is available.

But the question is: where do I host the WCF service? on both nodes? on a seperate computer? on 2 seperate computers at the same time?

Help! :)