Thread: a bit off topic but...
The ES compatibility list shows the 2i4 as being suitable, and since the preamp topology is the same across that series, the 8i6 should be fine. However, I wouldn't use the SPDIF I/O. Instead, see if your DAW can recognize both interfaces, with the 828 on FW400 and the 8i6 via USB. Most present-day DAWs should be able to cope.