Timbrens are required if you plan on running 35s or larger, regardless of using the Tundra conversion.
I ran into no issues running 285/75/17 tires with the Tundra set up.
I would recommend longer bump stops, if for nothing else to keep the coils from binding up at full compression. Timbrens may be the top of the line, but the Tundra guys are having good luck with much cheaper energy suspension bushings.
Back to the OP: One of the benefits of going with the wider Tundra arms, is the clearance from the sway bars and KDSS components.
Anytime you modify your vehicle there will be trade offs. Stick with cruiser parts and deal with clearing the sway bars, trimming the wheel wells and limited offset wheels.
go full Tundra and you clear the sway bars, but now are somewhat limited in wheel selection and width unless you are willing to have your tires sticking out past the fenders.
Everyone that has done the Tundra conversion has loved the way it turned out. It is more labor, and more parts, but if you are going to drop a couple thousand dollars on a lift, why not add 700 to it and get a wider track width, a little more travel, and more availability of spare parts.
luckily nothing has broken yet, but I know I have a better chance finding Tundra parts than cruiser...