Looks like that century ride has 6 rest stops - so think of it as 6 17 mile rides. So, definitely follow one of those training plans, start doing some 20 miles rides, then longer etc.
For me, doing a metric century is always a good enough gauge on how I will feel doing a "real" century - that would be equivalent in your case to making it to the 4th rest stop. The key is usually that saddle time issue - if your legs are losing power, you just ride slower. If your butt is killing you, it is agony. Building up saddle time is the only way to build up butt toughness - carve out the time to do a 60-65 mile ride in advance.