The Lake Ontario tour was 500 miles total and we were out for 9 days.
Agreed - some of the boys like to carry alot of stuff! I think its partially that they don't care about having stuff strewn about thier bikes, and partially that they enjoy the chaos of it all.
Roberta - TheJersey Devil Route linked above is a great bop from Philly and you can do it entirely with public transit. You could do it in 3 days, or 4 if you really want to take your time. Clem H would be perfect, thats what my wife rode. The sugar sand can seriously slow progress at some points, but it usually doesnt last too long. Overall its a pretty flat route with minimal cars, with the exceptions of a few areas where you need to hop on some paved roads.