Yeah manuals have cruise control I drive an MGZS and it has a manual transmission and has cruise control and I can also change the speed whilst in cruise control but I don’t usually do that as you can keep your rpm at like 3000 in 6 gear doing 65MPH

Yes they do! If your vehicle with manual transmission doesn't already have it, you can install an aftermarket one from rostra. They make kits for all car types. Extra parts are needed though for manual transmissions, one to tell if you have the clutch depressed and the other to tell if your in neutral. Make sure to mention that you have a manual transmission when purchasing a aftermarket cruise control