Yes, what you have mentioned will work. Double NAT won't be an issue.
I assume you are not planning to implement any access list or IP based traffic filtering on the router - because the router will not see any IP other than the FW untrust IP.
Yes, what you have mentioned will work. Double NAT won't be an issue.
I assume you are not planning to implement any access list or IP based traffic filtering on the router - because the router will not see any IP other than the FW untrust IP.