I'm in search of a 2nd car and am really torn between two cars I love the body styles on.

the z31 86- (Hate the tail lights on 87+)

and the 86-91 RX-7

Now, being stuck with a mustang for my entire driving history thus far, I am only knowledgeable with it. ( For the most part. I'm a quick learner. )

What I need to know is the reliability, simplicity, and modification capabilities of the two.

Give me all the details, please and thank you.