Was not a kit. Choose a "boiler plate" base model from RDM Industrial Products, chose the type of top they offered, figured out the T-Track type and its layout, sent them that information, got their quote, then had them build it.Is your bench a "self designed and built", or did you buy it as a kit ? Either way, it's a beautiful bench. Good job.
The bench I started with was their model A-109P-WD. They can build any size dimension and type of bench, out of most any material you want.
T-Track used was 80/20 brand, 1050 series in smooth finish. I had them space the tracks 7-1/2" apart to facilitate the use of Inline Fabrications' Junior model Ultra Mount for reloading presses. I am using Rockler T-bolts and clamps I picked up from a local wood working store.