Please do yourself a favor and get your head out of the " going the cheap route " when considering a trike.
Go for a good quality, COMPLETE CONVERSION KIT.
Going with training wheels will only leave you $3,000 invested in something you wish you had not done in the long run.
If your going to do this, do it right the first time?
There are those who will argue with that assessment but if you can swing it, do the full conversion and you will never regret it.
The training wheel variety has its own set of problems,The full conversion avoids these.
If money truly is a problem, go into the training wheels with your eyes open?
use the search feature at the top of the page and do some research?
I built my own and believe me i looked into every possibility trying to build a trike on the cheap because i have the mechanical know how to do so.
I checked out every trike component, buying one part here and another there and found that a complete kit is less expensive in the long run and i could avoid allot of installation and fitment challenges.
Dont fool yourself into thinking you can do without a raked triple tree for handling ability ok?
A quality tree can be obtained on this sight for allot less money than anyone else wants, Check out the folks on this forum for the best deal on a kit.
Beware buying a kit on the internet, They may be an old kit which had it's own design problems and are now out of production for a reason.