Is late series 2, most places that have the gaskets should have the grommets, otherwise the local dealer will probably have them, or replace the screws with bolts same as the neo setup
I'd go for the Turbosmart, it's easy to get the springs if you want to change them later & although nothing really goes wrong with them you can get diaphragms etc. Tried & proven.
Otherwise the Kando.
Just use the whole neo intake, the 33 iac only needs one plug unless you're running a/c? I just plugged it straight onto the neo & all ran fine, otherwise it's easy enough to make an adapter plate for the iac, I wouldn't bother trying to mate the manifolds together
/\ I didn't read all that but I remember the first time I drove a 20 I pushed the accelerator through the floor so hard there was calf pain, I hear you though with the price & availability of RBs getting worse for sure, just put a 25 turbo
I've only been in manual V35s but I'd guess 0-100 they'd be pretty even stock, throw an exhaust on them both the JZX will probably be slightly ahead.
They'd be close enough to get which ever you prefer the look & feel of.