Maybe you need to supply some more information here, you've said you are using a GSXR front end and inquired about a GSXR rear wheel, the easiest solution is to stay with the Suzuki stuff, that way there's no fabrication needed in the front and only a small amount at the rear, that includes small mods to the spacers to suit. If moneys no problem and you wanted more exotic mods please say so, the bike will look silly with a CBR rear and GSXR front wheels and a CBR front wheel would have to be modified to fit the front GSXR forks, even disc spacings or offset will be different......