I've been working on several stepper controller boards for other projects and I needed something small to do testing. The MendelMax 1.5 was a good option so I've started construction. These take a considerable amount of time to source all the parts and I purchased the majority from McMasterCarr and misumi. Both have excellent service, website, and very fast shipping.
I've been working on a XMOS CNC controller board and in the process came up with two prototype designs using two different Texas Instruments stepper driver IC's. The DRV8818 and the DRV8824. Both of these ended up being able to control the NEMA 17 steppers for RepRap and the NEMA 23 for my small CNC router .