I can't say which is best, but I think your options for off-the-shelf adjustable dampers are Protech, Avo, Spax or Gaz. SJ Sportscars sells Protech. Lotus Supplies sells AVO. RD Enterprises sells Spax. I don't think any of the usual suspects sells Gaz.
I'm waiting for someone to do a back-to-back comparison and publish their results, but the heat death of the universe might come sooner. Probably any of the above options would be an upgrade compared to the original equipment.