Need ability to define different types of SubTasks

Specifically, I want to have at least two types of SubTasks that when created automatically are linked to the parent story or bug.  The default SubTask works fine, but the additional SubTask that I need is for Bugs.  More specifically Bugs that are directly and automatically related to the specific User Story being tested.  We will use the Sub-Bug for bugs raised during In Sprint testing that focuses on testing of User Story Acceptance criteria.  We will then use the separate and independent Bug issue to log Regression defects.  By default In Sprint bugs are related to a specific User Story in the current Sprint and are expected to be fixed during the current Sprint.  That's a goal.  However, Regression bugs are not related to a specific User Story by default and are added to the backlog and prioritized along with everything else in the backlog.  Regression defects can still be related to one or more Stories if needed and they can still be addressed in the current Sprint if they are critical for the completion of the current Sprint.