The earliest MBP's probably need that heat paste thing redone, but 2008 and later Core Duo 2 MBP generally last as long as you don't flex the logic board (don't carry it by one corner), and keep it reasonably cool. One of hte older generation MBP had clips for logicboard that were ver fragile.

For linux, the US$7-800 core i5 toshibas and HP laptops at Costco work pretty well, except for wifi on the Realtek chip set. 8M RAM vs. 2M on a 5-year old laptop is a big diff.