I recommend against getting the full suit. (Had one) Get the Gladiator bib pants and the Next Safety Jacket as separates. (Have now) If you blow out a knee pad (and why) you're only out about half for replacement.
I guess my point is that a two piece suit give you more replacement options down the road. I rip up the knee pads quicker than the top and the pants are about $190. So I can get more use out of the top rather than replace the whole suit for about $450.
I suppose you could cut it in half if the knee pads blow out and get the pants then.
Just sharing my personal experience. Look for your best deal and get the Dainese, the stuff just works.
I agree that you should get the two pieces separately, thats what I did and Im glad that did it that way. I got the Viking pants and safety jacket. Not only do you not have to replace the whole thing if you mess it up (I too have found that the lowers rip up quicker) but you can wear just the uppers or lower depending on what your doing. I wear just the lowers for the less technical stuff and they stay in place much better than my separate shin guards.
As for sizing I got Large for both the uppers and lowers and Im happy with that. Im ~5 10 155 lbs and have a ~34 waist. You should try to find some place where you can try it on if possible, but if not call up Go-ride or Transcend and ask them about sizing.