If you are wanting to spend as little as you can, there is a Chinese fluidamper knock of by PRW. It is actually engraved with marks at 90*'s, not painted on.
For a bit more money (about $350.00 IIRC) you can get an Innovaters West damper. Probably dollar for dollar the best on the market.
I've posted before but I'm not a fan of elastomer type dampers.