Swap on a SOHC Vtec head(D16Z6 or D16Y8, supposedly the Z6 head flows better though), and redo the internals if you want to run some good boost in the future. so you'll have new internals and new bearings so basically a new engine.
Look on
www.thepartstrader.com , theres always someone selling a vtec head with all the other stuff you need.