FJ Distributers is soon to be releasing D15 rods. Stock D15 rods will hold to about 180whp, D16 rods will hold to about 230whp. But tuning is key here.
Otherwise, pick up a D16 whatever. D16Y8/D16Z6 if you prefer VTEC. Hit up FJ Distributers and get Vitaras with his Rods. That's $500. Stock cams will be good for 300hp. Do a rebuild of the bottom end, head if you wish.
Figure out a nice turbo for it, many people seem to like T3/T4's. Find a Intercooler on Ebay, go to RC Autoworks for charge piping and a down pipe. $150 will get you a Cast Manifold on ebay. Walbaro Fuel pump, DSM 440 injectors.
Don't worry about sleeving the block or a block gaurd. The block will hold upwards of 500hp, and so will the Vitara pistons. You can if you really want, but that's money better spent elsewhere.
If you search around, you can be at 300hp for less than $2500 including tuning.
www.turbod16.com is your friend.