First off, check out the reviews of both of these poles on our site as well as the Carbon Fiber Trekking Pole Review Summary. These will be very valuable in your quest for poles.
Next, it sounds like you're a first-time pole user. With that in mind, I think adjustable poles are a great idea. With these, you can play with different lengths until you find what's right for you. When using the trekking style, you place the poles beside you for stability and easing stress to your legs. The Nordic Walking technique places the poles behind you to use them to push off for increased speed. The NW technique works best with a pole that's about 5cm longer. Also a pole used in the snow is usually a bit longer. And sometimes length is simply a preference thing.
I would guess that you would use a 130cm pole to start. I'm 6'1" and my poles range from 125cm to 131cm with the longest being used mainly for really long and fast trips where I really focus on Nordic Walking technique. I like them for snow too. For more casual hikes, a 125 works out just fine.
If you are a big guy, the MSR poles you mentioned are good and stiff. Also look at the Alpkit carbon fiber poles- they are super sweet- light and stiff (a review of these will be posted within the next few weeks). Life Link makes some marvelously stiff poles too.
My wisdom to impart? Plan on buying some fixed poles in the future. They are super-reliable, silent, effecient, and absorb shock better than adjustable poles due to their single long shaft. Fixed poles are the way my friend...that is, after you have FOUND the way.
Ah, young grasshopper. Time and experience will guide you on the path to righteousness. For I am the inner, AND the outer.
Doug, the BPL pole guy