I'm not sure how many pounds of pressure you want, but I'd consider this as a DIY option:
http://www.gaussboys.com/store/index.php/magnet-shapes/blocks/b2506e-n42.html
Plus
http://www.thatpetplace.com/replacement-pad-felt-mag-float-125-glass?gdftrk=gdfV2226_a_7c268_a_7c6967_a_7c240751&ne_ppc_id=1463&ne_key_id=26445387&gclid=CITNzqr2v70CFZRr7Aod9GIANA