In the past, the "official" unlocked non-T-Mobile, non-Verizon model came out approximately two months after the initial release.
As others will tell you, there are options to get a functionally unlocked iPhone now.
Should I just get the tmobile contract-free iPhone 6 then? I want an iPhone 6 unlocked now and don't want a contract. Or is it better to wait for the official unlocked version (which will be hard but I can do it)?
You can always just wait until next Friday to buy after the initial people who bought it confirm that it is unlocked. Doesn't seem like there's a shortage this year for the 6.