I looked and the Suzuki is the DR400, the Kawasaki is the KLX400. They evidently are the same bike - different badging. Some years/models are true dual sport bikes with off/on road tires - other times they had smooth round street tires for Motard or Super Moto type riding (sliding around corners on the street).
I rode a friends KLR650, and it is pretty tall and heavy to be considered an "off road" bike to be tossed around.....it is more of an adventure tourer that can be ridden on gravel roads, fire roads, single track lanes, and loaded up with travel gear. It is a bit taller and heavier (over 400 pounds with fuel) than anything I would want to try and do real "off roading" with. When I was young we would try and climb the steepest hills we could find......and I can't imagine trying to pull the KLR650 off the side of one of those hills. But the KLR 650 is a great, durable and very capable motorcycle for riding on or off the pavement, and touring through the woods, or desert, or back roads.
If you want a dual sport you can throw around a bit easier....the 250 size bikes are fun - but highway speeds are pretty much limited to 60 mph on them. A 400 might be a good compromise. The Honda 450 would probably be a really good dual sport bike and it is not horribly big or heavy....although I had a neighbor with the motocross version and I could only touch the ground tippy- toe! And don't forget the Suzuki DR650 - it is a lot like the Savage but is more refined and has more HP.
And lastly.....the KLX250 may be the most affordable, lightest and best at the off road stuff. It is capable of 65 mph according to this article, and if you look around you can find some that have been taken care of.
http://www.dirtrider.com/features/kawasaki-klx250s-real-world-test/http://dayton.craigslist.org/mcy/4894827397.htmlhttp://dayton.craigslist.org/mcy/4894827397.html