crabapplemcn, I do not have an answer for you (sorry!) but since I went thru this "need answer asap" phase recently, I would suggest that you talk to/visit a local showroom where they have such a faucet on display and measure it. Try calling; typically they would answer those Q's gladly.

Sorry again for not being much help; just suggesting an alternative to getting a quick answer.

I usually do 5" but also depend of the sink.

Depends on the sink because of how splashback will occur. (Or may.) Too high and you might get a lot of splash.