I'd say go to ATP and get your CFI/I/MEI and try to get a job there. You'd get a ton of multi pic time with them and be able to get a job at the airlines faster that way. It sounds to me like they want your money at the fbo and NEED someone to be an SIC for them. Don't let them pressure you into something you don't really want to do.

At the FBO you work at would you also be able to get your II and MEI? It sounds like ATP would be a good option if not. But debt isn't a fun thing to have either. Aviation isn't the easiest thing to get into now a days and there is no right or wrong answers. I never thought I would be where I'm at now, it's not where I want to be. But I'm paying my bills and building time fast. I had an offer to go to the airline that hired me years ago but had to cancel because of my contract... and I make more money flying GA planes for now.

You just have to keep plugging away and try to do your best. Good luck