I just got hired at a regional earlier this year with less than 200 hrs for commercial flying and all of that was multi engine flying skydivers. about 800 of my hours was flying my PA24 around. I have over 600 hrs of cross country doing that and over 300 hrs night.
It is a viable path to the regionals. I honestly thing you are not going to skip regionals going that route though. But honestly I don't see you skipping the regional step, any LCC is going to want to see 121 time from somewhere usually.