Having owned two different drysuits, both of wich were tri-lam (typhoon and DUI), I will offer this piece of advice... Each suit is going to bring to the table certain pro's and con's. Think for a min about the progression of your diving, the environment that you will be diving it in, and then start to weigh the pro's and con's.
Of course this seems simple enough but far to many people, uh hummmm...me included, buy a suit that works for right now and not for the future.
I went cheap for my first suit, there was nothing wrong with it, but as I began to dive it more frequently I was more aware of its short commings and eneded up selling it and buying the DUI.
Fit is going to be one of the biggest concerns you should address up front. Some folks I know just dont fit well in a DUI off the rack, they have two options, look at a different suit or order custom. Its worth the due dillegence and in the long run, the extra time spent will pay divedends ten fold.
On another note, I hear alot of people say they tried on a Whites fusion and fell in love. Talk to those same folks after they dive the suit several times with fully loaded pockets (backup masks, wet-notes, back up tables, lift bags, reels, etc. etc. and see what they have to say. I have heard far to many compalin about the "sag" that occurs due to the skin not being attached to the inner liner..
Hope it helps,
Austin