You can use a UAD 4710d to get 8 channels in at 192k (4 pres and 4 line). You have to use a pretty weird aes snake from Tascam to Yamaha (can order from Redco.com in USA for 60 bucks).
If you are fine with 96k and below, you can use anything with adat out. A focusrite Clarett 8pre would work well.