So this one from suger creek (
http://www.usaknifemaker.com/index.php?main_page=shopping_cart ) is basically like the one from evenheat? I dont know much about them so I need as much info as possible.
The link does not show the model to which you refer.
The comparison being made is between a).the Big Knife Kiln by Sugar Creek Industries, and b).the Evenheat KF 22.5
When discussing kilns, the first thing I look at is chamber volume, and the exact dimensions that make up that volume. Two different different kilns can have similar volume, yet completely different approaches to getting to that volume. A kiln suited for firing a tall vase would require different dimensional structure (and door access) than one more suitable for heat-treating knives.
But the chamber volume, no matter
how it's formed, will give us an idea of the heating capabilities of the unit. Simply put, more volume requires more wattage, and the manufacturer will provide at least the minimum power to heat that particular size of chamber to a given temperature.
These two units are in the same category, meaning, for the most part, they have similar chamber volumes.
Since the chambers are close in size, you will probably wonder "will the Big Knife kiln still heat up enough?" Yes, it will, it will just take longer to reach that temp.
The only time this would make a dramatic difference would be for the person doing truly high volume and loading the kiln to the gills with every use.
Then the power advantage of the Evenheat would begin to shine.
As I mentioned above, I have only heard the reports of others concerning the Evenheat (I don't own one, nor have I used one). But from those reports, the owners have been very pleased.
I know of at least three people on this forum who own the Big Knife kiln- Rex McClellan, Rudy Joly, and Robert Hosmer (myself).
We're all are very satisfied with it.
Regarding controllers, much depends on what you want/need. As Rudy mentioned, there are ways to deal with the basic thermostat, and I have went that route.
Such methods served me well until I wanted to make some dies out of H-13. The steel supplier informed me of the heating schedule, stating that annealing is needed after forging. But annealing this steel requires that the temp be brought down no quicker than 40F per hour! 1600F down to 1000F (the point that cooling could be increased) means that I had to adjust temps every hour for 15 hours! (By the way, I tried the old "bury" trick- it didn't work for me.)
After that project, I definitely went with a controller upgrade.
So your need (concerning controls) will largely be determined with the steels you primarily use, and what you're doing to them.
If you're using the kiln primarily for hardening/tempering of "common" steels, your controller needs are probably less stringent than the more complex steels with detailed firing schedules.
From what I gather, controller cost is directly related to capabilities.
A controller with more "step" sequences (expanded firing schedules) costs more.
A controller can also have more than one firing schedule program. e.g., schedule "A" for O-1, schedule "B" for 440C, etc. This prevents having to reprogram every time you change steels. The more programs the controller holds, the more expensive it will be.
As a general rule, even the basic controllers will hold 4 different programs.
Here are the links to the two models I've been comparing (hopefully the links work):
http://www.usaknifemaker.com/big-knife-kiln-by-sugar-creek-orton-temp-controller-p-2624.html
http://www.usaknifemaker.com/kf-225-10wx65hx225d-w-setpro-control-240v-p-1387.html
If you decide that you don't need a controller, here is the link to the manually-controlled Big Knife kiln:
http://www.usaknifemaker.com/big-knife-kiln-by-sugar-creek-manual-temp-controller-p-2621.html
Good Luck,
Rob