I suffer from VWF(Vibration White Finger).I too used to get the,"Tinglies" and numbness.I defeated these using a,"Cruise Control" which allows me to rest my Throttle hand like I can rest my Clutch hand whenever needed and the road conditions allow.Even a 10/15 second break every now and then really helps.
http://www.aerostich.com/catalog/US/Vista-Cruise-Control-p-17006.html
Once you get used to it it becomes second nature.I have them fitted to both my CX and would never ride without them now.
I was also,but never got round to it,fit some,"Gel" grips,
http://tinyurl.com/5wff5mThese or similar should help absorb vibrations.I tried Foam grips but couldn't wait to get them off as they were too vague and got water logged too easy.
Both these options would save you hacking and modding the bars.
HTH
