I just had my HJ60's engine 2H rebuilt this summer, used Toyota OEM parts and sent the engine to K&S in Kelowna BC Canada to do the cleaning and other. Had 470,000 kms. Cost for parts about $5,000 CND, machine work another $1,200. I had ring damage in cylinder #6 and had to have a sleeve put in. I put in new pistons, new rockers, valves and cam ground, new pumps, bearings etc. Might concider new clutch while you are at it. The machine shop had no problems. I was warned that a new head and new combustion chambers would be needed but they were all good. If you need new add another $2,000. If you want a engine that will move you uphill fast, consider a low kilometer used turbodiesel engine instead. But there are also lots of hidden costs, ie.new exhaust, your transmission should be rebuilt at the same time or in very good condition and it may cost a few $$$ more. There are good aftermarket rebuild kits out of Austrailia that are cheaper than OEM.
Bob