Need to build a single LifeRay portlet.
1. It needs to save some custom configuration (securely) which is security keys for remote API URL
2. Using the configuration data - invoke the remote REST API and render the data returned.
I'm liferay certified and 8 years experience liferay developer. Expertise in liferay webservices and REST ful webservices integration. Let me know if i can help you, available via skype or freelancer chat.