Would it be possible to drop an Integra Type-R B18C5 engine into a '99 HX?? Let me know.

 

not only possible, but almost easy. the only thing to consider is cost. the b18c5 is really expensive. a full swap should cost about 4000-4500. and you could spend about another 1000 by the time you get it in, with a new water pump, timing belt, clutch, flywheel and anything else you might decide to add to increase performance.