Personally, I'd pull and do the heads but, being a tech I like taking things apart. :-)
Look at it like this, you know what the engine was like before the chain broke and there is no reason it should not be like that or better after doing the top end.
I always recomend taking the route with the least unknowns. One other source to check with is Potomic in VA, reasonable prices and pretty good service. (we bought a 103 from them with 90k and 195 average compression for 1700.00) I also installed a 102 from them that was exactly as described, 175 average and appeared to have fresh top end.
Weigh out the costs and benifits before proceding and from what I've heard I'd buy a mill from Potomic long before I bought one from adsit.
Project Smoker, '87 603 powered wagon
Hauler, 96 CTD can you say torque?
Toy 73 Cougar xr7 convertible
Acme Automotive Inc.