Since you already have a practical Altis, why not go for the BRZ/86? You've mentioned that this will be a weekend car and that you're still not a family man, so you don't really have to think of the need for a 5-seater. I say enjoy the freedom to have a two-door while you still can.

Unless your heart yearns for the WRX/STI, that is.
I own neither BRZ/86 nor WRX for now, but I plan on getting a Miata in a couple years' time in addition to my current FC Civic, so I'm "kinda" seeing myself in your shoes too.