Attack: Ray Striker D125CS (if the CS is aggressive)
Defense: Twisted [whatever you choose] 230CS (if the CS is calm)
Stamina:Twisted [whatever you choose] 145WD (you can try 230D, too, but I'm not sure if it works well on Twisted.)
I think that Twisted is better than Grand just because of the higher weight, but Grand can be passable for Defense as well. Twisted is still much better than Grand, though.
To improve your Attack combo, get Gravity Destroyer for the Fusion Wheel and Energy Ring and Galaxy Pegasus for the tip to make Gravity Destroyer D125R2F. If you play in Hasbro stadiums, get a Beyblade with an HF tip instead of Galaxy Pegasus.
To improve your Defense combo, pick up Hades Kerbecs for the Kerbecs energy ring and BD145 to make Twisted Kerbecs BD145CS.
To improve your Stamina combo, get the spin track from Gravity Destroyer and Hades Kerbecs so you can make Twisted Kerbecs AD145WD and Hades Kerbecs BD145WD.
EDIT: You have AD145? I missed that , haha. Replace 145 with AD145 on the Stamina combo I gave you.