if you have a pre 94 car, youll have to get a conversion from cable to hydro. i believe HASPORT makes a conversion harness. hydro and cable trannys bolt right up, but they dont work unless you have the car setup to handle either a cable or hydro tranny.
the pistons of the b18C will fit in your b18B. itll bump up compression and youll get some more power out of them. other than that, nothing will fit, with the exception of taking the GSR head and putting it on the LS block. but its better to take the GSR block and bore it to 84mm. youll have lots of torque with a reliable engine. LS/VTECs can be reliable, but that is determined by the quality of the build and the driver, which neither of those i have seen to be the right way.