Original Message

A commercial add-on is easy... if you have a lot of turbine already from helicopters some airplane Part 91 and 135 will take you off the street.  Adding on a FW instrument and multi-engine makes you marketable to ANY airplane job.  Work up to 250 PIC in airplanes (and you already have close to 1500TT) and you're hirable by the airlines.  

Doing a CFI or some other cheap flying side-job can build those 250 so you don't have to pay (banner tow, para-drop, glider-tow, fly Cessna charter, instruct, etc. and someone else will pay for those hours).   

It's not as hard as you think.  Just depends on what route you want to take and how near/far a flight school is near you.  If you're mil then finding a Part 141 school is more of a challenge to get GI Bill to pay for it but it's MORE than doable.