Confused Farmer With an S&T Internship and Questions

I only have two brain cells, so I didn't look at exit opportunities from S&T before I applied. After reading around (a lot) it seems to me that the IBD is the ideal launchpad to go to the buy-side (which I want to do).

I'm an S&T intern at RBC in London who wants to go to buy-side and wants to increase exit opps, so I'm considering trying to go FT or SA for IBD hopefully at a BB, but maybe MM, in NYC. Is this the best course of action? Which one would position me best to get me to the buy-side in a HF research analyst/ trading role or PE?

(A visa is required in London but not in NYC.)

Thanks for any advice in advance.