lots of good questions. First , goog choice on a brand of bike, I love my Trek. Schwinn has become more of a dept. store type bike. There are quite a few nice brands out there that have spent alot on R&D.
Can't tell you about bar-ends. I have drops and have quite a few hand positions to choose from.
Gel saddles? don't waste your money. I tried them a couple years age. It will only help if you have a really hard saddle, but thats only temporary. The cover will keep moving around on you.
Your best choice will be either a medium padded saddle of a hard saddle while using padded shorts. I hear some bike shops have cheap used saddle you can buy. Or try Ebay to buy saddles cheap. Finding a comfortable saddle is mostly trial and error. Try this link for more saddle info:
http://active.com/story.cfm?story_id...tegory=cycling It's called "The quest for the perfect saddle".
As far as storing a
ccessories, I use an under the saddle wedge bag for tools and a spare tube. I also had a small triangle shaped bag right under my top bar for keys, cell phone etc. Also don't for get to buy an air pump.
Nasbar.com and performance.com both have a wide selection. Just one thing, Don't but the following items on line. Gloves, helmets and shoes. This is only because these items you need to try them on first for a good fit. Also for clothing try a sports clothing shop. You'll find much more resonable prices.