There's always BigFinish .
Its hard to do a Whoniverse because the central appeal is the Doctor and their adventures and thats harder to replicate with other characters.
Plus money and budgeting are issues. Britian doesn't seem to have that big of a budget compared to the states.
I think UNIT could work the same way Agents of SHIELD could work but it would need a strong cast to anchor it.
Honestly i wouldn't mind Ruth being #14.