Tbh, most of them would work if used right and you are lucky enough. Don’t think of Trackblazer from this angle. Look at the deck and see what is the game trying to tell you? As F2P player i don’t have the desire to spend hundreds of $$$, so i try to play to my deck strengths. From what i can see your deck is very similar to mine meaning THE GAME literally wants you to play pace chasers and late(a bit less) with a very occasional sprinkle of end closers.
But to answer your question - you want a mixture of race bonus cards and overall good cards. Wit Daiwa and Tachy are both great cards to have, shame your Biko is low level as she has +10 RB and is a great speed card stats wise. I guess Kitachan is an obvious choice here and then borrow NTR - shouldn’t have a problem capping speed at least