I don't know the answers, but if you can link to a link station on 
echo-link, you might find some.  That sounds like a big project for a small 
result.  How far from home will you usually need to be and still connect to 
echo-link?  It's not the band alone, power to is an issue.  If you are 
running five watts, listening on the same band shouldn't be effected I would 
think.