[8695Beaters]

If you have to swap motors, do a B or a K series. Another D will bolt right in, but with all the other stuff you have to change, it's better to go ahead and do a B. Your Civic can handle a B16 or a B18, just get the right engine mounts. If I'm not mistaken, the Si came with a B16 and the B18 uses the same mounts. So if you can get some Si engine mounts and an Integra clip, you can build yourself an American Type-R (well just the engine). A K20 will get the most power, but it's expensive and really hard to swap. Since your Civic was designed to accept the B and D, then mounting the B will be pretty easy.

I say find a wrecked Integra with a B18B (94-01 non GSR or ITR), pick up the entire front clip, and swap in everything you can. That includes the engine, trans, wiring, accessories, radiator, ECU, and gauges. While you're at it, put in an LSD, since you will already have everything out of the car. Since the Civic and Integra are the same chassis, most everything should line up without too much issue. I would reccomend finding the shop manuals for the cars so you know what will fit where. Later on, you can do an LS/VTEC and make the whole shebang worth while. That is unless you find a good deal on a GSR clip. If you can afford it or save up a bit more, you can do it all at once and save yourself a bit of work down the line (if you do the VTEC engine later, you will have to change gauges, wiring, and some accessories a second time around. Better to save up if you are going to all this trouble in the first place). Plus if you use all OEM parts, then you can keep the reliability Honda is known for.

I am assuming your car is stick. If not, then also factor in the cost and work of replacing the slushbox with a man's transmission. Autos can't take advantage of real VTEC since they shift before the motor makes any real power.