OP, before this turns into a regional CA vs. ULCC FO discussion understand that as mentioned, it's extremely important to get your app in ASAP. Times have changed and there is no magic number where you may receive a call. Submit the app and update. In the mean time as you build hours, get involved in a union (if you have one), volunteer, and find ways to progress your career. I've talked to a lot of recruiters and friends in hiring and what they really want to see is career progression. Regional FO -> Regional CA -> Regional LCA is a strong resume. But with the hiring industry now, Regional FO -> ULCC FO/ACMI FO is also a viable resume, not including all the extras like education, volunteer work, etc.

Submit your apps now, but more importantly make sure they're accurate and correct. Having addresses and work history 100% accurate now makes life down the road a lot easier.