I agree. Of the three, the 6400K is bang on.
You might try a combo of 6400K and 4100K. However, make sure they will take the 4100K back in exchange for a second 6400K if it is not adequate. If they won't exchange, I would not risk it, get two 6400K.
I use T8 fluorescent, and on my dual tube tanks I use one 6500K and one 5500K for a tad more warmth (red). But I have tried this sort of combo with a 6500K and a 4000K and it was not as good.
On another issue, T5 is very bright light for freshwater fish, so a good cover of floating plants is advisable (or, like many high-light planted tanks, just plants and no fish).