Fair question and I should really remember that my past ventures into cars and planes has perhaps led to me expecting all modellers to understand what may have been generally understood in the past. I refer to a typical standard servo as not being micro or mini and not digital resulting in prices ranging from about £6 up to £15 depending on the gearing. You can get cheap digital but they will use more current and are really more suited for the flyboys where really accurate positioning is required.
I suggest you visit E-Bay and type in Standard Servo to see a range of options. There are many on-line suppliers and all will help you with your particular requirements and can be contacted by phone.
You may be aware that some Chinese imports may be of questionable quality and I have a drawful of such items that my fellow club members have had fail. I like repairing where possible so the bits come in useful.
Finally I should mention that some micro and mini servos has a max voltage of 5v and will be damaged by any voltage above this level. Personal experience shows that they will melt so beware.
Hope you can find the servo you need