Any advice on a career decision

UK student here. Going into final year at university, currently interning at a pretty well regarded MM boutiqe bank. I have an SA offer from a top BB/EB. Goal is to have the option of top PE placement (interviews) or not limit my options to do anything else e.g. set up my own business one day/MBB/MBA.

My question is should I:

A) Do the SA stint next year and do a masters after graduating (I'm thinking LBS MiM looks amazing, and I got a first last year so won't have to do the GMAT for it. I think I would really enjoy the course. Also looking at general masters in finance courses, LSE, Imperial, Oxf. Masters are kinda expensive as well)

B) Apply for FT and don't do a masters, and if I get an offer, turn down the SA offer to start FT somewhere else instead. If I take this option, what kind of an offer should I take over my SA offer? E.g. I probably wouldn't take an offer from the place I'm at at the moment, even though the culture is great.

Thanks in advance, any advice appreciated, specific or general!