Welcome to the site abhishekrawat1985!!!
I have moved your posts into your own new member thread so people don't get mixed up with who is welcoming who!
Sweet looking 250R, we don't see many of the clean green nowadays since the latest greens have been Special edition models.
In regards to your exhaust choice, considering you have already ordered the Akra, I guess it doesn't matter if the yoshi is better! Honestly, there is not a lot of difference when it comes to slip-ons, mostly looks. You don't have to buy a dynokit, but it will help get the most out of the slip-on. Instead of forking out for the dynojet, then if you are mechanically inclined, you can just shim the Carbies to match your altitude.
If you use the search function you should find some threads on the subject!