Awww Lindz, sorry to hear about Parker. You'll know when the right time to get another dog is. My kids would do the same thing - ask for another one right away. Doesn't mean it's the right time for you or even them really. If now is the right time, enjoy picking out a new companion. Parker wouldn't want you to be moping around and spend all your time sad. He would want you to enjoy life and enjoy the company of another dog. If the time isn't now, it's best to wait IMO.
Sorry, I know you miss him terribly.