Lynn,
Installing an exhaust brake does get complicated to say the least.
I am assuming that your Dodge Ram is a 94-98 since this is put in the 12 valve forum.
First things to consider, how many miles are on your transmission,
and how are you going to control the lockup on your converter?Why do i ask this? because without the lockup system the exhaust brake is useless on the automatic.
What is the retarding hp at 1500rpms, 2000rps, 2500rpms?
Those numbers are important because the if the retarding hp is too high at the lower rpms it will cause damage to your tc,
The tc clutch is weakest at the lower rpms, the higher the rpms the stronger the tc clutch becomes. Think of it like a bucket of water,
If you are swinging the bucket of water , the faster you swing the bucket the greater centrifigual force pushing the water to the outside of the bucket.
Between 1500rpms and 2500rpms you almost double the capacity of the tc clutch.
Last but definately not least, in 1999 Chrysler was buying back exhaust brakes that was installed as a factory option.
Why do you think that was?
It was because it was more cost effective to buy back the brakes than it was to fix the transmissions.
It is not that i dont sell exhaust brakes for automatics, i just think people should know both the positives and negatives of having the exhaust brake.
Personally having towed heavy trailers with an exhaust brake i know the safety benefits of having one in the mountains, and wouldnt be without one.
No matter who's brake you choose keep this in mind,
I make it my practice to keep my rpms high, shift out of od anytime your speed drops below 60 if you have 354 gears,
54 mph if you have 410 gears.
Whether they tell you you need it or not, it is a smart idea to install exhaust valve springs, better yet if you have high mileage change both the exhaust and intake springs.
I am not trying to scare you into not buying an exhaust brake, it is just the exhaust brake on an automatic should be chosen and installed keeping all of the above in mind.
The transmission will also require special attention, what are your transmisson line pressures at?
If the trailer is heavy enough , 3rd gear clutch capacity and 2nd gear band capacity should be strengthed to handle the extra load.
Shift timing on the transmission becomes extremely critical, as a transmission technician i have a habbit of using the terms
1-2 , 2-3 , shift . While this sounds right , actually on a dodge transmission it is the wrong terminology.
On a dodge the correct technical shift pattern is 1-2, 1-3,
there is no 2-3 upshift on the Dodge.
What does all this mean?
Most guys when they have a trailer tend to manually upshift from 2nd-3rd, or from 3rd back down to 2nd manually.
I know i am using the wrong terms again, but this is how most idenfify the shift pattern.
If the 2nd gear band is not full released before the 3rd gear clutches come on, you are going to do damage to both your 2nd gear band and your 3rd gear clutch pac.
Same is true when you go from 2nd - 3rd.
In first gear the rear clutch pac is on all the time in all forward gears, ie) 1st , 2nd , 3rd, and 4th,
In 2nd gear the front band comes on,
In 3rd gear the front clutches are applied and the front band is released.
You MUST make sure the front band is released before the front clutches come on, or you will have a bind up.
Make sure the person doing your work has a full working understanding of what he is doing. On an automatic it is not as simple as bolting the brake on.
Bolting the brake on the automatic is the easy part of the job, preparing the automatic for the exhaust brake is a whole different story.
If the job is done properly, it is a pleasure to drive the truck and it gives you good reliability, improperly prepped or a not prepped transmission can become a nightmare.
Attention: TDR Forum Junkies 
Sounds like a typical Banks (over) price! I think I will buy a BD or PacBrake! 
