It's interesting that you and I are in the same boat. My suspension tuner makes his own subtanks (copy of Enzo's) and wanted me to try them out. Since I am changing my valving from another company, I wanted to feel the effects of only that change first (so I can better help my customers). Down the road, I'll try the tanks and note the difference. Awesome concept!!
As far as other things to address (I take it you have a KX), definitely go with the heavier bumper in the back. My forks are coming back today and will have a bolder polished and gold anodized look with the nitride coating. For my Vet. Int. MX abilities, I think it's a bit foo foo, but my tuner says I'll be able to feel the difference so since we have an agreement going I will appease him!!
Should be able to have everything back together by the end of this weekend.