I think these pans on offer at Union Machinery are much too large for what you need.
A quick google search found this:
Possibly much more suitable sizewise and about half the price.
any ideas for the cooling system?
It's a little difficult to offer advice without knowing exactly what you are planning to do.
I mean on what scale?
Is this two or three or more than ten batches a day?
If you are going to just make a couple of batches I would just consider running the whole process in a well air conditioned room with a fan blowing air into the pan.
If you can keep the room around 18C you should be OK for small scale production, having some source of heat in the room working at the same time as air con will help to keep relative humidity below 60%RH.
You can use the same room for resting product between process steps. You pan a few batches one day, let it rest till the next day to crystalize all chocolate, than polish and varnish these batches.
If you are thinking about making it on a larger scale (many smaller batches a day) or you are looking for a very fine finish you may need to invest into air handling system that would keep your room conditions correct and supply dry cold air (40-50%RH and 15C-16C) into your pan. Your supplier of polish and varnish should be able to give you exact requirements.
If you just starting dont spend any large amounts of money on the set up. Get a small pan like in my link or one offered by Justin above (even cheaper).
To make good or very good panned product consistently you will need controlled environment (pretty much applies to all chocolate production). Because making it on a small scale is very time and labour consuming process failed batches are very costly.
Simplest way to achieve controlled environment is by using air conditioned room. I'm not sure what temperatures are like in Washington throughout the year or what manufacturing set up you have so it's a bit difficult to offer specific advice.
In general if you have a room with big domestic reverse cycle air conditioner that will allow you to hold temerature between 16C and 18C you will be OK for starting (make sure your liquid chocolate tanks are outside this room), you will need to keep humidity around 50-60%RH (add a heater in the room to drop or splash some water to increase).
From home improvement store buy an exhaust fan, something like this:
and suitable flexible duct.
Fix it so you can blow air into the pan (make sure your electrical work is done to local regs).
In this way you have cool air going into the pan at right temperature.
Pan your centres (slowly or even slower), smooth them.
Put them in a tub and keep in this room overnight.
Next day polish, varnish and rest on trays in the same room.
This should work just fine while you learn how to get what you want.
Portable air conditioner is not a good idea.
It will blow into the pan air that is too cold so if you take it out you may get condensation on product surface which kills it.
You will need to control the conditions in the room anyway.
Beware that panning is a noisy work as well.
Online converter says that 68F is 20C.
Do you know what is the humidity level?
From these two I calculate for you what is the minumum teperature of air that you can blow onto the product to avoid condensation.
You will probably need that room colder anyway for polish and varnish application and drying. We find that anything above 64F and 50%RH results in product sticking together when drying resulting in kiss marks.
This depends on product you use.
What polish and varnish agents are you going to use?
Do you have a specification frm supplier for the application conditions?
I would guess that it would be extremely hard to use polish and varnish at these conditions effectively. This is based on products that I know of and my enginering knowledge.
I would suggest roasting your almonds to almost scorched level before giving them a chocolate cover. Makes fantastic product.
If the temperature is 68F and humidity at 60%RH dew point will be 53F,
same temperature and 70%RH dew point at 57.5F and at 75%RH dew point at 59F.
If product surface temperature will be below dew point you will get condesation on the product and resulting problems with bloom and bacteria.
That means that if you blow a very cold air (like from portable air conditioner) into the pan which will slowly cool down the product surface to 50-52F and take that product out into hot and humid room you will get in trouble.