I use Torco GP-7 but I pre-mix. I think you should too. Injectors work till they don't then it's money time.
The china kits can be used. I had trouble with 1 piston. Sometimes the ports are 1/2 closed do to molding imperfections.
These kits are about 13 bucks in volume. ( I looked ).
Ya don't get much for 13 bucks IMO.