All things being equal, I'd get the B14 in MT... parts are almost exactly the same between the two cars (engine, transmission, suspension (except for the beam axle in the rear)... the B13 has a keen balance, but the B14 body is much stiffer (and there's more space inside...). Also, take note of the condition of the aircon... it's a b**** to fix if it breaks. That, more than anything, is a good reason to get a later Sentra. But if you've got the extra money for fixing it up, a B13 ECCS Sentra (especially if you can find one with complete trim and stock mags) is quite a looker... much like an 89-92 Corolla FX.

A U13 Altima would be nice... great engine... decent car... but parts will be rather difficult to find unless you live close to Banaue. A Sentra would be easier to maintain.