TXS0206A: This part is for a 4-bit SD/MMC card. What is the best way to level shift when using an 8-bit bus?

My application uses an eMMC device with an 8-bit bus.

If I connect a TXS0206A to CMD, CLK, and D3:0, what is the best way to perform level shifting on D7:4? 

I could use a 2nd TXS0206A connecting to D7:4?  Should I also connect CLK and/or CMD to the 2nd device? 

Or would a TXB0104 4-bit level shifter be a better choice?  TXS0104 only works up to ~24MHz and is not fast enough.