Hi Nancy
It seems quite clear in the Enphase iq7+ specs sheet that they are compatible with 72 cell panels up to 440W.
Assuming you are talking about LG Neon 2, which are a 72 cell panel.
We have a related discussion on Enphase IQ7X and + compatibility, I’ll post there and see if there is any additional feedback for you.
I also ran it through the Enphase Compatibility calculator, and it got a 
https://enphase.com/en-au/support-module-compatibility-en-au
From what you are saying, I agree that 603Solar sound like a good option.
Having said all that. I agree that whilst there may not be any compatibility issue, there would be significant clipping. So I would question Julie (or Enphase, or LG) as to whether that is the best combination.
Cheers
Marty