It sounds like your reasons to pursue military aviation and an opportunity to serve in that capacity are the some of the right ones. There's no doubt going that route and doing it properly will probably cost you the opportunity to make your way to a major airline job as soon as possible.

Only you can decide where your priorities truly are.

Many guys will probably get on here are advise you to do whatever it takes to get that major airline line number as soon as possible. But, very often, the ones offering that advice do so after spending 10 to 20 years flying in the military. Now, their 40 to 50 year old self is wishing their seniority was better while forgetting the unique military experiences they had in their 20s and 30s are impossible to quantify.

My point is this: Money, schedule and all the seniority an airline can offer you may be the end all for some. Doing the 121 job for 40 years, point A to point B with vectors to an ILS and hotel room waiting every night may work for some. Personally, I can't imagine doing this job from age 25 to the end.

Many of us did stuff only a small number of pilots ever get a chance to do. The friends I made are men I trusted with my life to and those relationships last a lifetime. The common experiences we shared, the challenges and the mission driven, goal oriented reasons for our daily efforts are impossible to quantify next to the simplistic nature of 121 ops.

So, if you have a shot, I'd highly recommend you take it. I think you'll find whatever sacrifice you make in seniority will end up being worth far more than it costs you.