The trans-go shift kit is fully adjustable according to your needs . You are the guy thats going to be beefing up the valve body and can make the proper/adjustable upgrades to what you beleive will make the transmission perform better . These adjustments can be changed at any time if you wish to change the way the kit functions .
The first kit you linked to is a recalibration kit which is designed to compensate for known issues and design flaws directly from the Aisn Warner factory . A lot of research and development goes into these little kits so dont let anyone tell you they are a waste of time or a handfull of trouble . These kits do exactly what they say and reletively simple to install
The second kit is an actual Shift kit that increases line pressure and allows you to make some hefty accumulator adjustments .
In my opinion , you should be able to get everything you need from the smaller recalibration kit if you include a few extras from Sonnax http://www.sonnax.com/units/329-A340E
I agree with you that members here should be looking at doing their own valve bodies using these kits . It may have to do with the scared factor or possibly peace of mind that they are purchasing something from a well known vendor and it has a warranty .
Not every member is willing to tackle a valve body kit on their own .