for the carpet i'd go here (then click on quick find)
http://www.accmats.com/index.htm
or here
http://www.jscspeed.com/mk3/interior/carpet.htm
for some other small interior parts you can go here
www.suprasport.com
this place has some good parts too
http://www.supracarparts.com/
then you can always try the MKIII parts for sale section on supraforums
www.supraforums.com