If you are "connecting" on the same booking, then whatever the booking engine will allow you to book. You are protected in case of delays. The MCT for QFi-QFd is 1:30, which is probably reasonable. I see sometimes of the year, QF94 connects to QF 702 , 1:40 later, or 5:30 later. If on the same booking, would be entirely comfortable with the 1:40 connection time, as worst case scenario you end up on the later flight. If not on the same booking (i.e. not protected) then I'd go the later connection.

If not on the same booking I'd be definitely looking at least a 3.5-4 hr connection, which allows for delays up to 2 hrs, and immigration 1 hr (and on the longer side if you don't have SmartGate).

The walk from international to domestic takes about 2-5 mins (2 mins if you know or easily find where you are going, up the travelator) from T2 to T1 or T3(for QF or VA departures) or about 5-10 mins (at ground level) from T2 to T4 (for JQ departures).

Minor comment, it does depend on time of year ... QF 94 arrival varies between 7:30 and 9:50, and QF96 between 8:25 and 10:30.