ventura is coming out in a few days, can i still buy a new MacBook Pro with Monterey on it?

You cannot downgrade the factory OS on any new model lines which were released simultaneously with the new OS, in this case Ventura.

However, an existing model line which has not had any hardware changes can sometimes be downgraded to the previous version of macOS. For example, if the Early-2022 model computer is currently being sold with Monterey and later this week the Early-2022 model ships from the factory with Ventura and the computer has not had any hardware changes to the Early-2022 computer, then you may be able to downgrade to Monterey by performing a clean install of macOS. This has been possible with Intel Macs under these very specific conditions, however, I don't know whether the same thing is possible with M1/M2 Macs with Apple Silicon because their boot options & boot sequence is a lot different from the Intel Macs and the boot process is partially unknown on the Apple Silicon Macs. I just made up the "Early-2022" model designation as an example.

probably; anything that has already been manufactured and loaded with the OS will have the current version on it.