Think about it from a risk vs. reward stand point. You have so far put together a nice resume. I am sure you would make a fine airline pilot. Is it worth the risk of getting a training failure on your otherwise good record? In the current state of the industry you just need some 121 experience and some total time to pad your resume. I would go to a regional hang tight for a year. Soak it up like a sponge. Then when you are nice and comfortable take the upgrade.