There is no need to replace the shift forks unless there is some unusual wear on them from lack of lubrication. The forks I have seen are the least likely to wear out.
The resulting shift pattern is one up, three down.
The kit will include a new bell crank, inner gearbox cover (which includes new oil level plug bolts).
On my conversion, the opening for the kick starter shaft needed to be enlarged a few thousands. Also, the opening in the outer cover where the neutral finder lever passes through needed to be enlarged slightly.
You will have to pay particular attention to the positioning of the Bell Crank Bush. The Snidal manual says the bush should be flush with the lip of the inner cover opening. In my kit, I found this not to be correct, mine needed the bush to protrude approximately 2 or 3 mm out of the the inside of the inner cover. With the bush flush with the cover as Snidal suggests, there was too much slop introduced into the shifter such that I would get a false neutral between 2nd and 3rd gear. This is something you will have to play with so that the bell crank engages the shifter fork with the least amount of lash. I had to add and subtract shims onto the bell crank shaft to get just the right amount of lash to eliminate false neutrals.
Remember that these kits are not mass produced on CNC machines and are better described as semi-hand made. As such, there is variations from one kit to another so that your skill at making small adjustments as you assemble the kit is of utmost importance. These imperfections are one of the most important characteristics of the Iron Bullets, once you get it dialed in, you can say contributed to the hand made features of this motorcycle.
Moving the rear brake lever to the proper left side improves the rear brake at least 100%.
I think Blasphemous has had some recent experience with this conversion and may be able to add some tips to this discussion.