So first, forget DCT cause it wasn't available at that stage. Second be VERY careful what you buy, as said before, there are some out there that have been tracked/flogged etc. After just recently attending the BMW M Drive day I can comfirm that they turn their cars over every 6 months, 11 or so at a time so there are a few out there that have had a relatively hard life...
Lastly, you are getting to where warranty is expiring with some 07 cars so take care!
Happy hunting and good luck with your purchase!