Best type of metal for turntable platform?

Look... I'm not knocking the SOTA (except for its looks :). If I dont solve this, then I might consider it. I just didnt want to be limited to ONE turntable in this room. I was considering a VPI Prime Signature in a year or two as the next TT. But with this room the way it is, I dont see that happening. the concrete blocks/wood as a footer does sound like the logical thing to do... So there's noooo other way to deal with a footfall im assuming? Is this why im getting woofer flutter/pumping with almost anything I do?

The point is, you might have to spend a lot of money on a localized audiophile bandaid solution instead of a few bucks by minimizing the actual problem. 

You don't need CNC, unless you yourself make it a requirement. What you need to eliminate footfall problems is a two stage approach. First stage, mass eliminates large amplitude low frequency footfall type vibrations. Second stage, springs isolate the turntable from the smaller amplitude higher frequencies that get past the mass. 

With a superior product like Townshend Pods your table will probably be fine even with your existing rack. People who have PM'd me about problems like this tried Pods and they work great in situations much like yours. They work even better in situations like mine, which is why it is still a good idea for you to build a sturdy low profile rack with a massive sand bed. As described above. 

You really should as a general principle ask the question you want answered. You came here asking about metal when really it is about footfall problems with your turntable. At least that is what it seems to be. Until it changes yet again....?

@best-groove:     A plinth could be more a work of art*, made of that.        If cleverly equipped with an air bladder; very efficacious against footfalls.                                                               * Some Panzerholtz laminates are leg-wetter gorgeous!

Well.. yes.. the original question was for the platform.. but since someone else brought up footfalls.. which was always a bigger problem.. why not ask to get as much help on it. Ive asked about it in the past but the info you guys are giving is better than anything ive hearf in the past. Again.. i do have a friend with a CNC machine that can make almost any type of metal platform.. so yes.. any info does help with that.