Hardrock, To download a correctly formated ringtone to your 8700 you need to post the tone to a site that allows posting tones for over the air downloading, such as the Downloads Feature of Pinstack. Once hosted, use you BB Internet Browser to go to that site, and find the ringtone you posted. Select it with you Browser and Click the trackwheel. This will open the ringtone player and start downloading the tone. Once it is downloaded, it will start playing. Now use the scroll wheel to move the cursor to the far right control of the three on the screen. Click the trackwheel and that will open the save menu. If needed change the filename to something you will remember, and complete the save process.
Now that it is saved, open the menu in the Profiles App on you BB and select Show Tunes and look for the recently saved file. Now you can play it and You can now use it as an alert tone for any of the options when editing a profile.
Hope this helps.