748-998 use a 10mm offset rotor, different axle spacing and different fork bottom offset than the 749-999 series. It is also set up for a speedo drive - so a spacer may be required.
The 848-1098 use basically the same wheel as the 999 (15mm rotor offset/5 bolt) but use a different axle. There are a lot of these around for cheap and would might be an easier swap.
or give him a call at 916.369.2509. He is more familiar with the little details and differences.
We get trade in on the base 1098 wheels for BST wheels from time to time. If you let Matt know he can contact you when any come up.