Hi and welcome.
1/ An EK9 does not have a D14! A variant of the EJ9 has though.
2/ Go with a B16A2 (DOHC VTEC).
3/ Yes it will fit.
4/ You will need everything. I.E. Engine, ECU, loom, gearbox and I believe the mounts as well.
5/ I hope you have or plan to upgrade the brakes and suspension first as these should be done before the engine swap.
Are these the only swaps you have in mind?