You need to have at least 2 IP addresses then, one for management, one for NAT.
Anyways, this is quite a problem for two reasons.
First, this same small-business scenario, where you have just one public IP address and you need to use this same address for remote management.
Secondly, if you need to allow SSH access from 0.0.0.0/0 and you run it on port 22, you get SSH brute-force traffic 24*7*365 - who needs this?
Someone should report this as a bug or feature request, now that junos runs on SOHO devices like srx100, we need to have support for seamless in-band management.