I sympathize with your position, Raid. I too have bought expensive gear not because of professional need but because I wanted it. And indeed I've enjoyed using this gear and don't regret the expense.
So... I would suggest you get what you really want. The Summicron-L is apparently an exquisitely rendering lens but you may find it easier to acquire later. The SL/SL2 is not ideal with M lenses and you lose AF too. Still, I think you'd probably regret not getting the SL2 at the outset, with the feeling you'd chosen second-best.
That's how I'd think about it, I think.
I bought a Q, but it was before the Q2 was known, so I harbor no regrets. It would be different now!