CA aftermarket is great.... if you live in japan. Here, its not too bad. all the things you'll need can be custom made for about the same price you would pay for the stuff in japan. It'll just take longer as its not premade.
you would need a long block, harness and computer along with all associated sensors. If you have money to burn, just get the front clip. all the parts you'll need are all there. you can get a clip for around $1750 from
http://www.venus-auto.com installation rates will vary, but figure on about $800 to $1000 for a rough estimate. that would be with wiring and everything.
once you start reading more about this motor, you will see that it is actually better than the SR20. they built the SR20 because the CA18 was too expensive and to well built to turn a decent profit on it.
McAdam