Looks like you're looking for something like:

Originally Posted by Intel

SL9KA 3 GHz 925 2 800 MHz 65 nm D0 4 MB (2x2) LGA775 05A
SL95X 3 GHz 930 2 800 MHz 65 nm C1 4 MB (2x2) LGA775 05A
SL9D9 3 GHz 925 2 800 MHz 65 nm C1 4 MB (2x2) LGA775 05A
SL94R 3 GHz 930 2 800 MHz 65 nm B1 4 MB (2x2) LGA775 05A

A quick search through PriceWatch turns up a list of Pentium D CPUs.

Here are some that match your needs for 3 GHz+ and 2 x 2MiB Cache:

$90.42: http://www.ewiz.com/detail.php?p=PD-940&c=pw
$95.00: http://store.memorylabs.net/inped925duco1.html

You'd be better off sticking with your 820 rather than spending another $100 on a slightly faster Pentium D.