[quick]

I had a similar setup on my MkII and the stock injectors worked fine for me.

I think you only need to worry about different injectors when you turbo the 5M-GE.

 

[quick]

A/F meters are usually a waste of time.

If anything you want something like the FJO wideband with datalogging so that you can take a look at what's going on with some kind of accuracy.