From what I have gleened from reading far too many of these websites:
5960 was first offered for sale in 2006, featuring a revolutionary in-house movement with the latest in technology. I would expect Patek to offer the 5960 for many years, however the fact that the 5960 is Patek's first in-house chrono should secure its place in history and looks to be a good bet to retain value over the long run. Oh yea, and people love the watch.
5970 was first offered for sale in 2005 as a continuation of the discontinued 3970, itself a continuation of the 2499. It has the same beautiful Lemania movement as its predecessors over the previous 50 years, which is far more labor intensive to manufacture and adjust. Because Lemania is now owned by a competitor many believe this fact portends the end of 5970 production, and recently it has been reported by "highly reliable sources" inside and outside of Patek that production will end as early as 2009--but who really knows? Resale prices of the 3970 shot up after 18 years of production when it was discontinued. Most would agree that the 5970 is Patek's current "iconic" watch offering. Oh yea, and people love the watch.
I believe the 5970 offers the more conservative purchase (i.e., least likely that you lose much if anything on resale--to me anything beyond that is all gravy).
Both watches are trading in the secondary market over list so you should be fine on either piece. I think you will find the 5970 is easier to buy at list price or even a small consideration if you are a good customer
5060 is about 40% above list and 5970 is about 20% above list so either one if you got at list price then would be safe though 5960P fetches better premium. I have both and love them as their sizes are very suotable for my 7" wrist.
my friends would love to get hold of some. I bought my at list in Jan around $49K but currently in the grey market they are going at $70K!!! Well if you could supply me with names I would be very much appreciated.