Probably somewhere in the neighborhood of 3-4 years.
Try this - base your decision on a company that fits your needs and where you won't have to commute. Do NOT base your decision on upgrade times because those change quickly. What's a quick upgrade today because glacial tomorrow.
You entering aviation at a really crappy time. If you're incapable of making a decision based on your needs, then take the FIRST job offered and build seniority.
Im just now starting to get where some will look at my resume. I may end up staying here until I get my 135 mins and then a lot more opportunities will open up. Im thinking freight dog and then maybe charter/corporate who knows. Hopefully the industry will turn around within my carer.