How do I allow http/ftp access to files I have uploaded?

You might check out a plugin like this one.

If you don’t want to go that route, I’d suggest using a page template and a technique like this to list out the files.

Lastly, assuming you’re using apache, you could set apache to allow listing directory contents (not the best idea, IMO) and then edit your .htaccess to prevent WordPress from intercepting that directory path.