500? Wow, you must have some great connections!
I've done all of this to my 929 and it was a bit more. Luckily I found some cheap used parts that worked. Below I have listed parts with prices I paid, some were bought a few years ago, others used.
- Bore, plate (Nikasil), hone - $400
- Custom JE Pistons - 2mm overbore from 929 to 980cc 13:1 Compression (no one makes off the shelf) $450 (I think the price has increased to $550 now)
-Rods - options available- Falicon (heard bad things), Carrillo ($950), or Pankl Ti (got mine used for $300, they retail for $1600 each)
-Head work - Port, polish valve job $800 (4&6 Racing Skokie IL) did a nice job, especially for the price. I'm selling mine that I had done through them because I bought a different head with Ti valves. The one I had 4&6 do also has oversized exhaust valves (valves alone were $33 each).