you can check out the key at www.sparksracing.com
the key doesn't do much. maybe just make the throttle response more crisp. it may make the bike run a little hotter too
the rev box will be no advantage until you build your bike. if you get a rev box, i would get the gt thunder box. the other boxes make the bike hard to start in the cold months. some of the boxes add a 1000 rpm's or so and other just remove the rev limiter totally.
the best mods i can say for the money are a cam/piston combo. with the service manual you can do all of the work besides the boring of the cylinder. you will be able to get a cam, piston, all the needed gaskets, and boring for under $400. this will definately make your bike wake up. it helps a ton. just remember, going big is not the key. you can make a 406 easily outrun a 440. the compression is the key. you can usually run up to 10.8:1 compression just fine on premium fuel at the pump. the piston alone is somewhat of a waste. the piston and the cam complement each other.

 

Sounds like I'll hold off on the flywheel key for now. I'm supposed to be getting my white bros pipe back on Friday. Was busted up inside & I have my wrench rebuilding the inside! I really have only had my stock exhaust running. The white bros pipe busted inside & clogged before my first ride. What I get buying used. Anyway I know having the pipe back will make a difference. I'll be looking at different upgrades to see what direction I am going to go with it! Thanks again & keep the ideas coming

 

....Get the flywheel advance key,its easy and cheep come with flywheel puller..its not night or day,but every little bit helps.Umm rev box is just a little also,but i know the one W/B's makes it hard to start when its cold..I'm not sure about the others.Scents you have a pipe,do a piston now w/cam..If you don't want to buy a new piston,heres something cheep to do..with the stock piston. Take out the base gasket,get a stock head gasket,grind the rivet Honda put in,and its a steel 3 pieces gasket,take 2 out and spray the one your going to use with that blk stuff for BBQ's..Put it back together,this will help up the comp..Sounds okaey,but its cheep...