"I do not want to have to tear it all apart in a year because its not fast enough anymore."
If that's the case mate, you need to go all out. Big bore kit, heavy duty rods, lightened and balanced crank, ported head, big valves, big cam, slotted cam sprocket, heavy duty cam chain/primary chains/tensioners, back cut gears, heavy duty clutch and springs, heavy duty oil pump,APE studs top and bottom to hold it all together, electronic ignition and coils, CR or Mikuni carbs, and a free flowing exhaust system. An oil cooler is a good idea, but that's a personal choice. Add polished/stainless fasteners, braided hoses and any additional bling, as necessary.
Of course it'll still handle and stop like a CB750 so think about having the frame braced, better forks, brakes, brake lines and rear suspension, wider rims and tyres, (18" dia front and rear alloy rims with heavy duty stainless spokes for added stiffness is a good compromise, or mag wheels if you want to run tubeless) new heavy duty chain and new sprockets, maybe a fairing to keep the wind off your chest at warp speed? Rear set footpegs and lower bars will help with cornering at the much higher speeds your bike will now be capable of. A steering damper is a handy thing just in case you quicken your steering geometry with the addition of a modern set of triple trees or shorter forks.
If you did the majority of assembly yourself you could probably do all of the above for around $10k, and (depending on spec) around 100 BHP would be achievable. Or you could just enjoy your CB750 as is for trouble free cruising, and buy a 10 year old sports bike with more BHP, better handling and braking than a CB750 the $10K worth of mods, for around $2K. Just depends on how much you want to spend, and what you want to achieve. Cheers, Terry.
