Is there a site that can help me find a desktop equivalent to my gaming laptop?

NotebookCheck is a useful starting point. Look up a review of your exact laptop configuration and check its GPU benchmarks. Some reviews include desktop GPUs in the comparison charts, so you can see which ones land near your laptop in actual tests.

Check the CPU separately, since laptop and desktop chips don't map neatly by name. If your exact configuration isn't reviewed, look for tests of the same GPU at a similar power limit.

Start with the performance you actually want rather than matching model numbers. What resolution do you play at, what frame rates are you getting now, and which games matter most? Desktop benchmarks for those games can give you a better target.

Same-name laptop and desktop GPUs can perform differently, and even two laptops with the same GPU may have different power limits. Buying the desktop version with the same number might get you more performance than you need.

Post the laptop's exact model and configuration if you want a parts recommendation. The CPU, GPU and memory are a good start. With those details, people can compare benchmarks and suggest a desktop build in the same performance range.

If the goal is mainly a desktop setup, you could connect a monitor, keyboard and mouse to the laptop and use a dock for extra ports. That won't solve every laptop limitation, but it's worth considering before buying a whole new computer.