XPS 8950, installing Linux?

If dual boot w/ Linux is main reason for the purchase, look somewhere else.  The XPS 8950 only supports Windows 11.  Lack of drivers and firmware supports will provide users with negative experience and disappointment.

Any recommendations for a similar machine ?

You may want to check out the fixed workstation Precision line.  Besides Windows, they have supports for Ubuntu and Red Hat Linux.  For example of a 3660  https://www.dell.com/en-us/shop/desktop-computers/precision-3660-tower-workstation/spd/precision-3660-workstation/s101dpt3660us_vp

Precision 3660 specifications indicates supports for the following OS:

The only issue you may have is with Bitlocker, the PC itself should run Linux fine.  People are using an xps 8950 with Arch. 

It is possible to have a dual boot system with BitLocker encrypted partitions. However, there are some issues that you may encounter. For example, when you enable BitLocker on a partition, it becomes unmountable and Windows will not boot anymore with an error saying it’s unmountable1. One solution is to use two thin boot partitions with a shared data disk between the two. You can encrypt the data disk from one install, copy the Bitlocker key, and then boot to the other side and enter the key for the data drive on the other install. Now both OSes have access to the same encrypted data. Only one of these OSes could be bitlocked at boot time2. Another solution is to make one of the Bitlocker deployments ignore the TPM. You can control this using group policy. It will be less secure because you will have to store the key in plain text on a USB drive. For this reason, you should use a different PIN for each of the two partitions1. The available settings can be seen here: BitLocker Group Policy Settings.

can also use a virtual machine software