I find extremely difficult to give a valid advice here for various reasons - including the fact that passive pickups sound different anyway according to the guitar used but also to pots resistance, cable capacitance, input impedance...
IF you want something not too weak compared to a X2N but clean AND bright, here is what comes to my mind : the pickup musn't find its power in a high inductance but rather in a strong magnetism - with a limitation due to neck position: it musn't have too much string pull, or it will generate stratitis...
IOW, I'd think about a stack with a relatively low inductance and some ceramic magnet(s) - inspired by the hot noiseless Fender Strat PU's mounted in Jeff Beck Strats, for instance, rather than by a SSL5 sounding stack.
That's all I can say for the moment. Hope it's not too useless...