2000 4x4 3.0 Flex (vin V) with 100k+ miles

Just started to misfire (#5) so I'm considering injector replacement. Searched the threads as to suggestions & didn't find anything definitive.

Questions:
Can vin U injectors (non Flex) be used without problems? I'm not going to use E-85. Some thread comments are yes, some no.

Has anyone that has done this switch able to comment as to issues or performance?

Any comments/suggestions as to replacement injectors? If you have replaced with "other than" OEM U code injectors, what's your opinion of your replacement? Any truth to Mustang V8 19lb injectors as a replacement?

Or........... should I simply just replace with OEM stock Flex injectors & be done with it?

Your suggestions/comments are appreciated.