DIY Rack

Well, after long searches and racks that just cost too much in my mind, I've decided to go the DIY route.

I've got products sourced for every part of the rack so far except the contact between the floor and the rack. Ideally I want some type of adjustable spike so I can level the rack off on my generally uneven floors. This has been hrder to find than I thought. Any suggestions?

Sorry I can't be more specific about what is I am looking for, its the type of thing that I'll know when I see it.

So any direction the good folks here can lead me will be much appreciated. Oh and any suggestions for DIY materials in general would be fantastic.

Cheers,
peter