The first trike PhatAzz Trikes produced was the Atomic Zombie "Streetfox" basic design. an entry level trike made up from various frame and parts from a "recycled bicycle" The first thing i needed most was to train myself through YouTube Vids on how to weld together hunks of metal... After two rolls of wirefeed wire, a couple of slight burns (welding COMMANDS respect) the pieces were staying together!!!
So, if you feel that you can build a trike yourself, you will need some basic tools and maybe some mechanical aptitude, you can be whizzing down the road on a "bike" (trike) that does not give you a stiff neck and sore wrists from the rider position of a normal 2 wheel bicycle (we call them "leaners")
The other alternative is to work with the designer that has the shop,tools and experience to put together YOUR ride that will draw attention wherever you go.