MDIF2231-4E  Large NEMA23 IMS motor with Flying leads and Encoder $294.50
This unit is the one we're "borrowing from Rich".  

With 7:1 gear box (single stage) Maximum Backlash 0.070 degrees
MDIF2231-4E-G-7  add $190.  

A Flange is recommend:
MDIF2231-4E-G-7-F   add $28

Same motor with 14:1 gearbox (double stage) same price 
MDIF2231-4E-G-14-F  $512.50 total

2-3 weeks for motor alone
5-6 weeks for gear head.

MD-2131-3.0  Stepper Motor ONLY, no built in Controller, no Amp for $90
IMS has a motors with built in amp, without an indexer (MDM series)  $197

INFO on gearboxes at
http://www.imshome.com/md23_gearbox.html

Distributor: Western Technology  (Morgan Hill) 1-408-465-2600 
Contact: Heidi
Tech: Raleigh  (x122)
www.westerntechnology.com

Another Tech from IMS:
Randy Brummer    760-966-3162 (San Diego)