You might consider the VPI aluminum cones that are used on the Scout/Scoutmaster/Aries turntables. They are just over 1.5" tall, and are threaded. They can be purchased direct from VPI, or from online stores such as Elusive Disk (click on following link):
http://www.elusivedisc.com/prodinfo.asp?number=HW-19FUJR
http://www.elusivedisc.com/prodinfo.asp?number=HW-19FUJR