@monkeygirl35,
So many questions!

MobileRead has all the answers too!
Yes, it's now possible to sync sideloaded mobi books on your iPad & Kindle -> follow instructions in this MobileRead Wiki "
Kindle Sync with non-Amazon eBooks on Windows"
Yes, it's possible to sideload your mobi files into the Kindle iPad app -> follow instructions in this MobileRead thread "
Sideloading MOBI files to Kindle for iPad"
And for accessories, there's dedicated threads talking about
covers and
lights for the Kindle that you can check out!