Most of the suits today are of good quality. This probably isn't the answer you want to hear, but you need to try them on if you really want to pick out the best.
Suits have different cuts depending on the brand and line(Bare Nex-Gen is a 5-panel suit, I believe the Bare HD Trilam is more cuts. The DUI TLS350 is a 12-panel suit, IIRC). I've been told the Dive Rite 905 fits a large, round waist so reminiscent of N Florida(
), while the Bare's are more slender. Don't quote me though, that's only what I've been told.
Personally, I'd say buy what you can get a deal on unless you either 1) don't like that suit for whatever reason or 2) really have your eye set on a certain suit. Me, I bought my DUI TLS350 because it was brand new, old stock, and I got it for $1400. I really like it, but I also really appreciate the Bare suits, and probably would not pay full-price for a DUI. There's plenty of good suits out there without the price-tag of a DUI.
For warmth, you're going to want dry-gloves, believe me. My smurf gloves(those blue PVC lobster gloves) are the single best investment I've made in cold-water diving, by far. I got the SiTech Glove Lock system, which from what I can tell is a copy of the excellent DC ring system. The original, older style SiTech Quick-Cuff system has some drawbacks(prone to rolling the O-Ring and leaking, difficult to don/doff). If you don't get zip-gloves, I'd definitely get the SiTech GloveLock or DC Ring systems. What the hell is the point of having FREEZING cold hands with a body insulated by a drysuit? For instance, I can easily do 35+ minutes at 40*F and only JUST be getting chilled in the fingers, whereas before with my 5mm Xcel wet-gloves I could only do 5 minutes comfortably, and by 20 my hands were definitely painful. Cons of the smurf-gloves is they aren't the greatest choice for digging as they can puncture.....so if you're going to be digging a 7mm mitt may be a better choice.
For your undergarments, check out this guy on ebay:
eBay My World - rondel101bjrr I have one of his undergarments, and so do many others on here. I have NO clue why you would want to spend hundreds and hundreds of dollars on brand-name undergarments when these do the trick. They work great, simple as that. As for your base layer, I'd check out a local sporting goods store, Campmor, or Cabela's. Again, you can overpay for brand name Scuba-specific base-layers, or you can just buy base layers from the rest of the world at 1/4 the price. I used polypro for a while which worked great, then Uncle Sam said "give it back" so I had to buy some of my own. Went and got some Duo-fold undies from Campmor and they work fine.
You might infer from my post that what really counts is your warming layers, and I'd agree with that. The drysuit itself is only one small part in the equation, and all the major brands are decent suits. Find one you like based on personal preference/price range, buy it and have fun. There isn't a gold-standard suit for everyone.