Trans cooler?

Just serviced trans on my 98 LSC changed the filter and had it flushed. Did not look to bad considering the previous owner was going by mileage (37000) and was told they did not need to get it changed.
I am going to install a trans cooler. So question is which one I read the tech page here and super cooler was recommended. I am considering a Tru Cool with a 45000 btu rating, dimensions overall are about the same so it appears it will install in the same place. Is more btus better in this case? Anyone used or have any feedback on this brand?
Any thoughts on external oil coolers on this engine?Also considering having the coolant,and powersteering flushed as well??

Lots of questions but I really would like to get it right the first time

Thanks Rich

45000 may be too much for your application. I would go with around 30000, make sure to bypass the radiator.

Tru Cool is a decent brand. I would just get the B&M cooler you can get from summit-racing for about $50, the tru-cool I had was made out of aluminum and very fragile so be careful the B&M is much more sturdy.

Get the other fluids flushed... they are 10 years old.

I have the Tru-Cool 40K cooler and bypassed the radiator with no issues, but it will require different mounting. Before that I had the B&M super cooler in line with the radiator and it worked well until mods started to overtake the capacity.