When you get a chance use the search box in the upper right corner and use the google option to search for, leaking transmission and valve cover leak.
Very few forum members have found it necessary to replace the "head gaskets". Perhaps you mis-spoke as $800 for a head gasket replacement seems rather inexpensive.
Welcome to the forum and enjoy your car, but be prepared to do a lot of the maintenance yourself; It will save you a lot of frustration and money.