Fully sync two iPhones work and personal

Hi all!

I two iPhones, work and personal. My work iPhone is a 4s, and my personal is a 6. Using the smaller iPhone is a PITA, plus I hate carrying two iPhones. Is there a way to make my iPhone 6 display my iPhone 4s' callerID when calling people at work? It would be nice that when I dial a number, right before the call goes though, i get a popup, that says. "What number would you like to call from?" That way, I can just leave my work phone at my desk at work and only carry my personal.

I can already get email, texts, and inbound calls (via forwarding). Its just outgoing calls, that i cannot seem to find a free solution for.

Thanks for the help in advance.

Matt