Where do I get the memory? I need 2x2gb ddr2 sdram 667Mhz no parity no ECC

If this is your Mac, you can upgrade the RAM to 6GB.

https://everymac.com/systems/apple/imac/specs/imac-core-2-duo-2.0-20-inch-aluminum-specs.html

Macs are fussy about RAM. Both Crucial and OWC are reliable vendors with high quality RAM.

One well-regarded source: https://eshop.macsales.com/shop/apple/memory/iMac/Intel_Core_2_Duo

The 2.0 and 2.4 GHz iMac models from mid-2007 use the same memory, which can be found at Data Memory Systems.

You're welcome.