What about tallow? If you can use tallow, that would be better(IMHO) than palm.
If you must have a vegetable oil only soap, use more palm than coconut. I would use something in this range for a first soap:
Palm(or tallow) 60%
Olive Oil 20%
Castor Oil 5%
Castor Oil will help stabilize the bubbles, and give better lather. If you can't get that, just add that 5% to the Coconut Oil or Palm.
You aren't going to get the creamy lather that lard gives, but it won't be horrible.