FES/NMES recommendations?

I had a quintuple nerve root avulsion a few years back and my doctors have recommended me trying to use a NMES device to stimulate the nerves (or muscles directly if nerves are indeed damaged) to promote some muscle growth and flexation. The issue is that my medical provider recommends a device that I am just not comfortable with. For me, this is a permanent thing, there is no recovery and I would like this device to be the best it can. Their 'national contact' with the provider is for a BodyMed ZZa500 EMS unit for $150. I went online and you can get them as cheap as $38 (new) and this strikes me as both shady and cheap ass device. Anyone else have a FES/NMES device recommendation?