a lot of med students take a research year between third and fourth to apply build up that experience; at a handful of med schools that is built into the curriculum. Your med school might support you doing that through some mechanism. There are also a handful of external mechanisms like Doris Duke
Home | Doris Duke Charitable Foundation
here's a list of what projects/folks got funded in last yrs competition (notice that the PIs mentoring students who won the award tend to have been funded at some point in their career by the same foundation).
2018 Clinical Research Mentorship Grantees | Grant Recipients | Doris Duke Charitable Foundation
def dont do a PhD just because you want a marginal edge at residency (see my answer to u on reddit).
If you're interested in academic medicine and, in particular, surgery then get into the best possible medical school you can, ideally one with plenty of protected time for you to build up a nice research resume. Doesn't need to be basic bench science and, in fact, the vast, vast majority of surgeon scientists dont do basic science rather more clinical and then translationally oriented research.
moving to premed as op is premed.