IMHO. Build a static HTML sitemap for humans and use a Google XML site map for there purposes. I've tested sites without static sitemaps using only .xml versions and ALL my pages got picked up. Specifically I did this with a gaming review website and the results were nothing short of astounding. No B.S. top 5 rankings in under 3 weeks. The sitemap alone didn't achieve this, but it was the only thing I tried that went outside my normal practice.
Internal links are important in my book. One thing I do is on each page I put a link using that pages main keyword(s) string on the bottom of each page directed back to the home page. In the copy of each page I use at least 2 links pointing to 2 other pages within the site using the keywords of that page.
What I've found is I get more double listings using this. Try it. I don't think you'll be disappointed.