Welcome with the strong dollar to yen atm the minute I would think buying from Japan would be your best bet if you cannot cross reference anything locally.
Sites like rhd Japan and crooober should help also amayama for oem parts although more and more is getting discontinued now unfortunately.
Another option is the Japspeed radiator I have one if these in mine and it works very well but not sure if they still sell them.
Most people opted for the civic style radiators to accommodate lager turbos.
Wasn't the one at mega money but another one that popped up so had a little bid and to my surprise I won it.
Yeah the trd ones are just branded defi gauges but very rare don't think they made that many in the first place.
Check the engine earth is good you can do this if you have a set of jump leads connect one to the negative post and the other end to the engine block.
Check voltage at the starter motor with a multimeter.