From what I know, the Just Jap gear is from China. That being said, China gear these days seem to be getting better.
It depends on whether you reckon its worth paying extra going for the branded gear, for the slightly better flowing and cooling rad's and intercoolers. But IMO even if you went the Cooling Pro stuff, it would still be a massive upgrade over stock gear, and that they are pretty good bang for buck.
I personally use an ARC intercooler core and a Trust oil cooler kit so I can't give you any guarantees on the Just Jap stuff. The radiator is still stock for now mainly cause I ran out of funds
Ps. Where are you getting your quotes for the Trust oil cooler? That seems quite expensive