I would have thought that 4 cans of clear should be enough (providing they are the larger 13oz/400ml size cans). You could probably do a pre-flattened finish guitar with 2 cans, and you might get by with only 3. The neck should be made from maple and so be smooth (plus you have a rosewood fretboard which you won't spray), so you won't need to put too many coats on that.

Whilst they should be going on 'wet', keep the coats relatively thin and don't be tempted to spray to much on at once. That way leads to runs and a lot of annoying repair work which slows you down. More thin coats are better than a few thick ones.

If you plan to scrape the binding, rather than leaving it all green, then do it now, before the paint hardens too much - which makes the scraping a lot harder.