in consideration of the current value i would definitely say that POS is the way to go. Mining would only be usable if we change moneysupply per block.
So what interest rate do you want to use or how do you calculate rewards per user? Fully mined coins have low interest rates (of about 1%) which means that we need a much higher rate to "mine" the remaining coins and to make microCoin interesting again.
Maybe CaptEmulation could help when he comes back from holidays?
Edit: Seems like i overlooked that you have already arrived a decision .
I just think it might be fair if we keep about same interest rate with PoS as microCoin have planned with mining.
and if I remember right, it was 1000/block as far as 100,000,000,000 is minted.