Hey Carter, the MH1 6.0's are a good projector, but for our fairly large headlights, you might want something with a 3" lens. If you're working on halogen headlights, I definitely understand why you are considering them.
If you are set on the Mini's, TRS has the Morimoto Mini D2S 3.0 (which is based off a Q5-R projector) coming out on January 1, and its supposed to outshine the MH1 in terms of output, and obviously the ability to use D2S ballasts and OEM bulbs is a plus.
Here is a thread about a members build where he shaped the turn signal similar to look like the facelift, I plan on doing the same on my build, and wrapping the piece when its trimmed in brushed aluminum vinyl:
http://www.xoutpost.com/bmw-sav-foru...my-turn-2.html
You're right, the Spyders are still on backorder from the manufacturer, I'm in contact with them but still no ETA on a new shipment, those were great as they accepted Hella E55 projectors, so I used EvoX-R's for a member on the boards that came out great.
If you were to buy the Depo P53's for $350, you can buy the UHP LED rings from a seller on ebay that fit into the headlights, for $180. However, the Depo projector is not too great, especially on the halogen units. And the only projector that will bolt in to the Depo headlights based on bolt pattern is the Valeo D2S projectors from the older Audi's and BMW's in the early '00's.
Trust me, I've done my research haha. Good luck man and check out some of my posts and other threads, I also have a couple threads on HIDPlanet talking about a build on Depo's, long and short though its just too rich for me. I'd rather do a similar build to the above picture, use some SMD LED rings and EvoXR projectors and call it a day.
Hit me up if you have questions or want to talk lighting, I don't want to clog your thread up!