couple of questions first:
which B18C do you have - GSR or Type R?
do you have the transmission?
is the mount kit for cable clutch or hydraulic clutch?
since you had D15B2, i assume this was a DX model with 5-speed transmission, correct?
for any swap, you use the engine wiring harness that was originally in your car and make the necessary changes to it - you will need a P72 ECU and you will need to convert the car from DPFI to MPFI and convert from OBD0 to OBD1 which will require a ECU jumper for OBD0 to OBD1 - a lot of suppliers (like Boomslang) for the jumper incorporate the DPFI to MPFI wiring changes into the jumper as well as providing wiring for the 4-wire O2 sensor, VTEC and knock sensor - much easier to go this route - you will still need to make additional wiring changes to your harness for cooling fan switch, injectors, etc. - you will also need to extend wiring for the MAP sensor
you will need axles, intermediate shaft, modified shift linkage, throttle cable and fuel line from filter to fuel rail
since you will be boosting it, i would suggest you get a different intake manifold, especially if it is a GSR engine.
you will need to take a big hammer to the inner fender area to provide clearance for the alternator - Hasport instructions describe this pretty well and also list what other parts, like engine mount bracket, etc. that you will need
you will also need exhaust to the back of the car in addition to the turbo exhaust manifold, etc.
before you install the engine, you should install a new water pump, timing belt and timing belt tensioner and not a bad idea to replace front and rear crank seals and oil pan gasket - a lot easier to do before you install the engine
EDIT: since you will be boosting it, you need to seriously look at swapping to an aftermarket front cross member and half size radiator in order to provide adequate clearance for the turbo and piping
