Good desks to intern on

Generally, PE opps are harder to seize from an S&T background than from an IBD background. This is because PE - at least from the strategic value-add perspective - places a stronger emphasis on understanding an organisation's structure and performance capabilities than it does, say, on financial markets. That said, if you're interested in distressed debt HF exits, I think you'd do well to rotate across credit and securitised products (as two of, I assume, your three rotation options). Credit is more technically demanding than equities, so you'll get your microeconomic fill there (that will, in some small way, be applicable in the event you get a PE interview), while securitised products will have PE firms (e.g. Cerberus) directly operating in that market themselves. Credit and securitised products, for obvious reasons, will also give you a good education should you wrangle your way into distressed debt at a fund.

That said, I would caution against setting your sights on "exiting" this soon. While it's good to have a game plan early doors, transitioning from S&T to HF / PE after just a summer isn't so much an "exit" as it is a change in direction - you're also unlikely to develop a truly deep understanding of each asset class in the 2-3wks you rotate across each desk (at least not sufficiently deep an understanding that you're gonna blow the PE / HF recruiters' minds). If I were you, I'd do some preliminary reading on whatever desks it is you're allotted and then go about doing your utmost to get a FT offer. Once you've done 2-3yrs on that desk, your options will be a lot better than straight out of university (especially if you went from a target to a BB).

Good luck.