I have some web sites you need to study as well as their links.
http://www.kenkifer.com/bikepages/touring/
http://www.crazyguyonabike.com/?o=QzzM
http://www.adv-cycling.org/mag/companions.cfm
http://www.faughnan.com/touringbike.html
http://www.mikebikes.org/gear.htm
http://www.thedairyair.com/10kofusa/10kofusalinks.html
The Machka site at
http://www.machka.net/ is also a good site, she use to post on here but lately haven't heard from her. She is probably the most experienced person that ever posted on this forum.
Also don't be too concerned about your physical conditioning. When I decided to go touring about 15 years ago I wasn't in that great of shape for cycling long distances not alone loaded with extra weight. so I did about 4 weeks of short mile loaded training routines that got me home every day, then left. My touring legs actually came about 4 weeks into the first tour. Keep in mind, that I was in my 50's when I started, so the physical conditioning took longer then it would for you; but you could get your touring legs while doing the tour.
Also to say your going to do 100 miles a day is over-optimistic to me too. Some days may be nothing but climbing, or riding into a head wind all day, or raining all day, these days you may be lucky to put in 40 miles not alone 100. Also if your not in real good physical shape going into it you can't expect to do 100 miles on your first day with a loaded bike that you admitted to being completely foreign to; you may only do 25 to 45 miles before pooping out. There are too many varables to say your going to put in 100 miles a day. I've done loaded touring for 15 years and there are some days I can do 150 while on others may only do 35; of course I realize that I'm way older then you and you might be able to do more. My last tour I finished about 4 months ago was my toughest only because I'm pushing 70 and sleeping on the ground has become a literal pain; so my next tour is going to be ultralight/credit card touring where sleeping in motels will become the norm rather then the exception.