Not quite true, but almost. The SL Premium Package does not require a Sunroof. But all the other packages do. Even the extra options like the DVD navigation or chrome wheels also require a sunroof. This information is based on the following MSRP data (link below).
http://biz.yahoo.com/prnews/021101/laf082_1.html
For comparison:
Murano Front/rear head room: 40.7/ 39.7 inches
Jeep Liberty Front/rear headroom: 40.7 / 42.1 inches
Normally these measurements are without the sunroof. We own a Jeep Liberty Limited, w/Sunroof and it has a lot of headroom that I *think* would be ok for your height. But since the Liberty is listed at exactly the same front headroom dimension as the Murano, it seems like it would be reasonable to find one with a sunroof and try one on for size.
So what am I doing here in the Murano group with a very nice 1yr old Liberty in the garage? That's the wife's car that she loves (it's a Jeep thing - the Liberty is a tank). The Murano's for me in town and the family for travel.