Would be mines but mines it's not lowered though, I have an old school look to mines it may not everyone's taste but I love it.
Do you want wheels that stay under the rear lips? I used to have 15 X 7, 0mm offset wheels with 215/60 tires and they stuck out about 1". I currently have 14 X 6, 6mm offset wheels with the stock 195/75 size tires and they do not poke out from under the bed lip. There is plenty of room behind the tires so I think a 7" wheel with 25~30mm offset it should fit under. I am planning to get 16 X 7, 25mm offset wheels with 205/60 tires in the future.
I have plans to do a 20 x 10 or 20 x 12 on the back once i'm done with mine, we will see once I get my frame and rear end narrowed.
I had 295/17s on the back of my 82. I think they can handle the width as long as the offset if right. I used mustang style aftermarket wheels
i had some 245s on 95 mustang 5 stars the offset sucked so they rubbed the shock plate in back on 5 in blocks but they tucked