they aren't common at all. There's maybe 10 cars in Atlanta with a k swap. There's thousands with b series. K swap will run you 8000-9000$ minimum if you do the work yourself. That's a stock swap. Turbo built motor another 5000-7000. Its big money.
Set some realistic goals first and decide what you want and what your budget is
wow
and i recently baught a civic with a k24 and type-s tranny for 8,000