I would replace:
1. All of the small hoses that are on the head and oil cooler (pretty cheap).
2. Water pump if it has any time on it at all (very easy to do with no heads).
3. Any exhaust system parts that look questionable (you have to take them
apart to get to the heads anyway so now is the time).  Defineately replace
all exhaust gaskets.
4. Oxygen sensor
5. Coolant Temp sensor and o-ring(cheap)
6. Thermostat and o-ring(if hasn't been replaced recently)
7. Studs/Bolts/Nuts on exhaust system and heads.

Hope this helps,
Ken Wilford
http://www.vanagain.com
John 3:16
Phone: (856)-765-1583
Shop:   (856)-327-0027
Fax:     (856)-327-2242