We use Klim gear and feel it's the best stuff out there, bar none. Not sure what size? Here's Klim's sizing chart http://www.klimusa.com/f/sizes.html
One thing to note on colors.. Klim calls black "Gray". If you want black, order "gray". If you want gray, order "light gray". Clear as mud? Let us know if you have any question, that's what we're here for.
Here's what they say:
The ride started with a nip in the air. Thirty miles later it is sunny and warm. Like a chameleon, the Dakar Pant, with its controlled ventilation chassis, changes to meet the demands of any condition with little adjustment. The Dakar can adapt with the help of 20 inch mesh-lined zippered thigh vents and a mesh-lined rear leg vent. Adaptation does not come at the cost of performance and durability. The Dakar Pant is built with TNP heat and abrasion- resistant leather panels on the inner legs, Cordura® fabric for strength and highly reinforced knees and seat. Be ready to take the lead no matter the condition with the Dakar Pant.