Session persistence based on source IP address

I have a similiar requirement, but in my case the LTM is acting as a SSL pass through device. Only way I can persist is based on source IP. Now here's the problem; some clients use distributed Proxies. What I thought is to created a Data Group per client. Then somehow do a lookup to these Data Groups and then just direct each data Group to a given Node. In that way no persistance is required, the client's SSL communication does not break. The trade off is that these specific clients never get load balanced (unless there is way to select another node, only if the primary node is not available); of course everything else should be processed as per normal. Any ideas how this can be done?

 

 

I get the feeling the irule could be pretty simple (or am I being a total novice!)