I have replaced sprinter's rare jumps with some japanese ones (aka Dubai scrap) in good condition. They are same in height as of GS 150. No alteration required just plug and play.
Result: Bike pechay say thori uth gaye hai, mud guard say space ziada hogaye hai so no more issue of mud guard touching. Bike considerably become comfortable as the jumps are longer and has more space to move. Happy with comfort level now. Using these jumps for 2 months now no single problem occurred.
I usually ride average at 60km/h speed. Occasionally, I go to 90 and 100 - 105km/h. Found no real issue of brakes. You may need some inspection whether to put original brake shoes which should grip properly.
3. HARD SEAT:
I am also looking for some softer seat. I will try as bro 'tucknologi' mentioned.
4. SLIM TYRES:
The tyres are slim but the bike is still grippy and I have felt the same grip at higher speeds. You can change front rare with 2.75 but might be disappointed as the handle bar will become heavier to move around. I also asked my specialist mechanic and he simply did not recommend a bigger tyre. Yamaha YB has the same tyre size and there is no issue in these sizes.