It's hard generally to get buy side experience as in (1), so I think on balance if your goal is to be a quant trader, Worldquant is the obvious choice, the caveat being that you must be ok with working in Asia. (3) and (4) don't look like attractive options for what you want to do. (2) might be ok, but generally quants at BB work on pricing (exotics, structured deals etc), so unless you want to trade these products at the buy-side later, it doesn't seem to align very well.