Joseph,

To put it simply, yes. Just visit an Apple Store ask an associate your questions and then place your order. The Apple Store often only stocks models that are preconfigured as found on the Apple Store web site. Note however they sometimes stock "upgraded" models with more memory. This is often the case for the MacBook Pro models.

You can customize your iMac to your exact specifications. Just note that according to the Apple Store policies, a customized Mac cannot be returned. So keep this in mind.

After you choose the model with the processor speed you want, you can customize such as :

- Memory
- Hard drive
- Keyboard and Mouse sets
- Pre-installed Apple software applications

Good luck with your purchase and thanks for your question.