I use a Meier Audio Stepdance. It's successor Quickstep is even a little better. Running on low gain at 2:30 from Ipod Classic (EU version) LOD. One of the best portable amps out there for a reasonable price.
Got mine today. Running it fro my Fiio E12A right now. Very nice first impressions.... Ipod Classic 120 GB Apple lossless > E12A> HD700. Treble is much better than what I was afraid of. In fact it did not bother me till now.
You will hear the clicks with every open headphone, else it is not open. For you the Bose QC25 would be the better choice. You will not even hear your worst enemy coming from behind knifing you, that's for sure. So if you want an open can, you will still be aware of your surroundings.