I could be of some help...but I have to tell you something and ask a few questions.
The channels are very deep. Are you aware that this is going to take very long time to be machined. You've mentioned 1/8" endmill which means 1/16" per pass...10 passes at least altogether. Considering the fact that you will probably not be able to machine faster than 5 in/min, this could take a long time..
Is this supposed to be some kind of heat exchanger?
Send me your 3d model in IGS or STP format, or DXF or DWG drawings to:
tex707@net.yu
and I'll see what I can do.
Regards
Peter