Becoming a Navy Corpsman.?

So I want to become a Navy Corpsman and then attend fmss. From then on work my way and prepare myself for BUD/S or SARC training. Haven't really decided yet cuz they do similar jobs but ever since I was little I've wanted to be a SEAL corpsman. But I'd gladly serve as either. But that all starts with getting HMA rate which is currently overmanned. I've been talking to my recruiter and he keeps trying to talk me out of being stuck upon HMA, telling me they haven't had any openings for corpsman in a month or two and that I should take another rate and if HMA opens up before I get shipped out they will switch me into HMA. I really just don't want to get stuck with a job I don't want and never get a chance to try and become a SEAL corpsman or SARC. Any advice? Should I take a different rate and pray I get switched or try and wait it out?