Some USB serial adapters may work, some may not. Many support speeds higher than 115200 bps, but they may not allow "just any speed" (the ones that you mention probably will be supported, if they allow any such higher speed). It is up to the manufacturer to provide such a driver.

However... At the end of the day, what have you really gained? It isn't as though you actually will see higher throughput, except in some very obscure applications. The practical bandwidth limit for a single serial channel is about 100 Kbps. We can get into the reasons for that, if you are interested. In any case, any high-speed data transfer will require hardware flow control, because of hardware and Windows limitations, keeping the raw data rate to much less than you might expect.

Dick