Several ways to deal with the battery. Some people ditch the battery and run hughs set up for battery less operation(kick start only). Ive built a few with batteries and I attach to the swingarm. If you run this set up, you need to make sure the swing arm can fully move upward without hitting the frame. You can also get a gel battery and put it below the swingarm if you arent putting shorter shocks on. You can also turn it side ways and put it in above the swingarm. You just need to make sure you are checking all your clearances for swing arm movement,chain,fender and everything else you can think of that could be a problem.
Shocks......Rebel bolt right up. There are also Progressive shocks available all over ebay that bolt right in. I think they are 412? I cant remember off hand. You can ask sellers on ebay what the eye width is to make sure if you are worried about bolting it right up. As I state on my site, you should have the shocks you plan to run on hand if this is the first time you are installing one of my kits. It makes installation simple. I watched my buddy install the kit for the first time in approx. 4 hours from start to finish. He saw me build a few but he found the kit installation simple. A pre made hardtail takes about the same amount of time to install. Both have their fair share of work afterward to work out. This kit is no different. You have to figure out locations for starter relay ign box(if you have one)and reg rect.