Q1: I’ve looked for “faucet supply lines” to the specifications on the tag but none of them fit this bottom connector look, has it been modified or do I need a speciality line?
Underview
Topview
Q2: I’ve seen recommendations for 2 hole faucets for this situation, but with copper tubing I wanted an at least somewhat experienced opinion before I started ordering. What do you recommend for this type sink?
Or put in one of those glass rinsers that they have at bars. You can get one for like $40 and they're great.
Another fine idea. I've got a soap dispenser pump in mine.
Filtered water is another option to fill the extra slot.