Question about engine swap?

I just bought a 1991 Honda Civic EX with a D16a6 in it.
It has 197,000 miles on it and burns oil bad, but runs pretty good.
I either want to replace with the same or up it a notch to a JDM D15B VTECH, or a D16Y8. I don,t want a built engine, just something I can add a intake, and exhaust to, pretty much a nice peppy daily driver.

I checked out the engine swap pages, and saw that these were direct bolt ins. But, need more info as far as will I have to change my tranny, what about the wiring harness.

If it is truly a pull the old out, and put the new in, turn the key and go, Then I want to do it. I know there are a few other steps than that but you get where i am going I hope.

What about buying the engine on e-bay, is it worth it or find a local engine shop?

Here are some sites... I hope they can help :)

http://www.hondaswap.com/forums/index.php?showtopic=29749
http://www.honda-tech.com/zerothread?id=1508680
http://www.honda-tech.com/zerothread?id=131949

And here is one on Ecu codes
http://importaddiction.fws1.com/custom.html


Good luck!