They would do it, but you are in the wind more throughout the day (more upright position) and therefore it will take longer and use more energy. Either way they are a challenge to ride (a century that is). The 30-60 mile charity rides would be fun on the Treks you listed - just enjoy the ride on it and try not to turn it into a race. I would pick a bike for the majority of your riding, not the extreme one day possibility of a century. The 7.5 and 7.6 are very nice bikes for all round riding and are great commuters. You could get a nice set of bar ends for a ride similar to being on the hoods.