It's socket 462. not 642 😀
Almost any cooler will do the job, a good one would be aluminium, but with copper insertion, and a 92 mm fan, Titan made a lot of those, they should be easy to find and cheap.
Just be careful to not crack the die when you mount the cooler.

Titan TTC-CU5TB. Small, copper, easy to install. Looks like you have Athlon Thunderbird 1.4 ghz which tend to run very hot.

Also, make sure you put a dab of thermal compound on the center die, not the other dies, otherwise, it will die.

Also, if you've never installed a heatsink on one of these chips before, be ready for a learning experience.

The foam pads in the corners look quite deteriorated (most of them are after 17+ years) so they won't help to stabilize the heatsink during installation quite as much as they used to. The absolute worst thing you can do with these is apply pressure unevenly on the heatsink because it will tip. This was always a bad thing, but without sturdy pads to protect the die, you'll crush a corner off quite easily.

Many people have zero problems with this, but a lot of it comes down to the heatsink you're installing, the tool you're using to do it and the method with which you're going about it.

Also, the other thing to watch for is slipping with the screwdriver (or whatever tool you're using) when bending the heatsink clip. Most motherboard manufacturers didn't bother making the clip area EMPTY until the end of the Socket A era, so there were always lots of traces and SMD components to crush into oblivion right below the clip you're shoving a screwdriver into.

Ideally, if you can find a fancy cooler with a lever or screw based locking mechanism rather than one with a standard clip, you'll greatly decrease the chances of damaging something.

I'm sure others will give their input on the best tools and methods for installing heatsinks on these things too...

I put tape around my screwdrivers when I remove a heatsink without the clip on it and I had to remove the heatsink since the thermal compound was a mess on my HP OEM (ASUS A7V8X-LA) motherboard that has an Athlon XP 3000+ (2.1GHz) CPU. Wish I had an A7N8X motherboard at hand (the one I had until 2011 lost the MAC address on the integrated network card, which was weird).