You totally have the right idea, start slow and work up with accuracy and precision. Not only does playing slowly build this but allows you to earn more control and finger strength. Surprisingly enough i noticed after a while of shredding that my fingers were faster but pressing down lighter. So latley i have been working to bring up my clarity which meant playing slower and more accurately using more force in my fingers. I would suggest starting around 80 bpm and go up by either incriments of 10 or 20 when practicing. Once you reach accruacy at 120 you should be good for a while. Get accruacy at playing up to 32nd notes at that speed. Rhythmic and tonal control as well. The benefits from playing slow rather than just building speed are these. better precision, better accruacy, more powerful fingers, which results in greater clarity, greater depth and control fo dynamics even at extreme speeds, and the ability to speed things up allowing for muscle memory to fill in the gap of not being practiced at high speed.
Honestly, just start at 80 and go up as fast as you wish. Just do the math for how fast you can push yourself. IF you can do 32nd notes accurately and cleanly at 80 then you can do 16th notes accurately and cleanly at a speed of 160. if you can push this to 120 then you would be doing 16th notes at 240. Speed isn't everything, i worked up to being able to play obscene speeds like 240 - 280 and it's seriously only valuable for certain styles of music. Mainly death metal and shredding. Msot rock and metal is slower than this and requires much less speed but greater control. Also if you are going to be doing charomatic exercises get a few different ones and practice different note patterns. Do triplet patterns using your first second and fourth fingers and vice versa.
Hope that helps you some dude.