Assuming your transmission is definitely beyond economical repair & you are unwilling/unable to pay for a replacement at your Hyundai dealership, all I can suggest is that you contact your local breakers yards.......the Tiburon is not that rare a car & you should be able to locate a low-mileage write-off with (say) rear-end damage.
Many of these yards are linked via internet/telephone agencies who can deliver parts (often with a warranty).........try Yellow Pages or a Google search.
Tiburons arent highly common. I have 3. Onw transmission was needed and could only be purchased from CA. But anyways I have a stock 99 Transmission. For Sale. If youd like to purchase get back with me.