damper dynos

[spitfire4v8]

The industry seems to favour the SPA damper dyno, certainly the few damper manufacturers ive visited have all had machines from this company .. but what else is on the market. ? I dabble in suspension and dont want to spend massive money .. something secondhand would be ideal but these things never seem to come up for sale on the used market!
Does anyone know what options are available for reasonable money. It's for occasional use only .. think fairly serious amateur level rather than professional level of use.
cheers