It really isn't that complicated for most people. It becomes more complicated if you have back or neck or shoulder problems.
For most people, I don't think zones are necessary. Maybe better, but not necessary.
Not to be a shill for flobeds, but it's really a good business model (at least from the customers' point of view; I have no idea how much money they're making, LOL!) because they have people there you can call who can help you decide what will work for you, based on your weight and height and sleeping habits. Then they will ship you pieces that allow you to adjust the bed in various ways for very little or no extra money, depending on how long it takes you to get it right. They offer memory foam and latex so between the two combinations you can usually find something you like. So I'd guess that about 80% or more of their customers get a bed they are happy with from them. And what is great is: It won't wear out in a few years, and you can always change it / upgrade it by changing the firmnesses or materials inside the mattress, as time goes on and things change with your body. (I have no connection to flobeds. In fact, I am one of their FAILED customers because I simply did not like the feel of Talalay latex. But they took the mattress back and refunded my money minus shipping, no questions asked, no hassle!)
There are other web sites that offer cheaper deals on latex but less liberal return policies and if you search here you will find those companies and some of their happy customers.
if you really don't care that much about looks(though even this can be dressed up quite a bit so no one would even notice it wasn't a normal mattress) you can build your own wooden slatted platform or buy one, and build your own mattress much cheaper than flobeds with just a little more work and a lot more flexibility.
See my thread on building my own or some of mccldwll's threads on zoning etc.. My idea - which is working out well for my wife though Im still experimenting with mine - is to either use a spring base from a cheap or old Sealy, then add something like the following: (this is my wife's mattress):
from top to bottom:
1" MEDIUM HR FOAM
1" FIRM HR FOAM
1/2" SUPER FIRM HR FOAM
1/2" SUPER FIRM HR FOAM (Yes, 2 layers of 1/2" Extra Firm)
We happen to also use zones but this is not necessary. The only difference in her's, above, wtih zones is that for the top 1/3 of the mattress she has 1" medium over 1" medium instead of 1" medium over 1" firm which is what she has for the middle 1/3. The bottom 1/3 doesn't really matter that much. We chose Medium over Extra firm so that we can use those to interchange in other areas if necessary.
The total cost of this mattress (not counting the springs which we got from our old Sealy) is about $85 and this foam is rated to last 15 years. Though I doubt it if really lasts that long. For this price I'll be happy if it lasts 3 years!
On my side, since I have back and shoulder issues I have used the following with some success, though I'm still experimenting:
For my top 1/3:
1" SOFT PU FOAM
1" MEDIUM HR FOAM
2 AND 1/2" SOFT 3LB OR 4LB(?) VISCO FOAM
NO BOTTOM LAYER OVER SPRINGS
For the middle third:
1" SOFT PU FOAM
1" MEDIUM HR FOAM
1" VERY FIRM HR FOAM
1/2" SUPER FIRM HR FOAM (ONLY 1/2", NOT 1" AS MY WIFE'S)
Because we are using the "Shell" of the Sealy once you put the sheets on it this looks like a regular mattress. My wife's even has the top still on it from the Sealy - oh yeah, and that adds about another 1/2" of pu foam and some dacron on top.
So far, this is the best mattress I have ever slept on. My wife loves her's. I still have back problems which may not be solvable with any mattress. But my back problems are much better now than they were with the Sealy even before it wore out completely (at 3 years in).
However, the same mattress above can be made without springs, by adding just a 5"-6" VERY FIRM HR CORE which costs maybe $100 for a twin. Or you could go out and buy a used or cheap mattress and tear it apart for the springs and "shell".
The thing about zoning is it really is not difficult to do. For example, let's say you're building a King size bed. A king size bed = 2 x extra long twins side by side.
An extra long twin is about 38" x 80". So you divide the 80" into 3 and come up with 3 sections of 26-and-2/3" each x 38" wide. You then buy, say, 6 pieces of one inch foam of whatever type you like, for each side of the king size bed. I'd say that you buy 3 medium pieces and 2 firm and one extra firm, some combination like that, maybe a couple extra pieces to play with. And 2 full extra long twin size bottom layers to go over the springs, of EXTRA FIRM, one half inch thick each, as I described above. OR, if you are using a 6" core instead of springs, skip that Extra firm 1" layer.
The pieces tend to stay together on their own, but if they don't you can either use a little spray glue made for foam, or you can use a tight elastic sheet around them or anything else you can think of - just a big piece of elastic maybe? If you use the shell of a spring mattress, the shell holds them in place.
You can substitute latex of either Dunlop or Talalay or "jungle" type for any of the layers and you can substitute memory foam for the top "1-2" layers (personally I think 2" is too much memory foam, though).
Hope this helps someone who wants to build their own mattress.