Sampling rates:

44.1 KHZ. 48KHZ is needed for video work.

I have compared recording between 44.1 and 96khz and I could not find a noticible difference. Although 96KHZ gives you the psychological impression that it is better.

But remember, by using 96KHZ instead of 44.1, you will cut your track count into half. This also includes cutting plugin instances as well.

Almost all professional sound cards support 96KHZ anyway. But when actually recording, 44.1 khz is the chosen model.

What software will you be using determines to some extent what sound card is better suited. What do you have in mind? I will avoid USB2.

You can assemble DAW yourselves or better... research exactlty what parts you want and have a reputable professional place build them for you.