Martin and Keith hit it on the head - 60-90 min boil will give you all the isomerization and SMM volitization that you need - ASSUMING you keep a good, rolling boil throughout.
Urquell probably had a longer boil because of an inefficient kettle OR because using a hard boil would create hot spots and darken the wort.
At home, if you've got a good, stainless or dense aluminum brewpot and adjust your air/gas valves for an efficient burn, a good, rolling boil without hotspots is easy to maintain. In fact, most homebrewers have to cut back on the boil intensity. (Martin actually pointed out to me that I was "boiling the Be-Jesus" out of a Saison at a Big Brew a few years ago - has since been corrected)
If you use a long boil to concentrate or carmelize wort, add the bittering hops no earlier than the 90-mark. I think hops (much like over-cooked vegetables) have a dull, papery, "vegetal" flavor.