Welcome to the forum!
If you want to change your interior you can have it vinyl wrapped. Several have done so and it looks good.
If you are looking for pedals without the M logo there are several sources. If you like those I don't think you will get any grief since they are inside the X.
I have an SMG M3 paddleshift wheel on my X. I purchased a used wheel on Ebay and restored it to like new for about 1/4th. the cost of a new wheel. Here is a link to the installation procedure. You may want a different wheel but the changeover will be very close:
http://www.xoutpost.com/bmw-sav-foru...ions-pics.html
Do you know the history of your X? How many miles?