Re: 7.5*17 / 8.0*17
Both of then will take anywhere between 205 to 245 width tyres!
40 or 45 profile will depend on the space under your arches!
Try find some one with similar size and try them on!
You'll probibly want to run spacers (HR do good ones) to fill your arches, Don't worry about the bearings, I've never heard of them failing!
Dan