Research Intern or RA for thesis-based MS better for eventual PhD?

[crypticname]

Hello!

I have an offer for a funded master's in Biomedical Engineering. I also have the ability to complete a year as a paid research intern in the same lab (which aligns with my research interests). My ultimate goal is to complete a PhD in Biomedical Engineering (not at the same institution). I'm wondering if completing in MS will help or harm my PhD applications- I'm not sure if missing out on a year of eligibility for the NSF GFRP will greatly affect my applicant profile, or if the additional experience from the MS would outweigh that? It's my understanding that I would be completing similar research with either option, but it seems to me that I would have a lot more time in the lab if I wasn't taking courses at the same time. 

If anyone has some insight, I would be extremely grateful!