There's a Gateway DX 4860 that came with that CPU, but that CPU was first launched in 2011, NOT 2006.. You can upgrade the CPU to an I7 3770 for about $140 and it would still be a decent PC to continue using.
Might not work depending on what BIOS updates are available for it. The generation specific variant he's looking for is the I7 2600, the 3770 is newer and might not be supported.