With the manual trans get the best bang for the buck, either large injectors or a heavy fueling box. If the power is too much for your clutch towing just tell your right foot too take it easy or drive with the new found power like you would with a gasser, keep your foot off the floor. With the auto a person can not do this because for one you would tear out your transmission and two the transmission line pressure is dependant on foot throttle placement, the more throttle the more line pressure. With more power your foot does not travel on the throttle as much for the power you need hense less line pressure with more HP = a big no no.
I would get the DD ultimate power module or the EZ comp box.
Hint: -- email address removed -- has a used DD ultimate power module for sale at a bargain price. It works great and was used very little, I know, it use to be mine. Way too much power for my stock transmission with DD stage I injectors. The nice thing about the box is you can adjust the power levels 1-5 and within those levels you can adjust when the power comes on with a seperate 1-5 level.
I was going to have DTT TC and VB upgrade put in but could not find some one competent enough to do the installation so I sent the module back for a refund, thats another thing he has great customer service.
Moderator, if I have done something I should not have, sorry, and please edit my post.
I should also add I am in no way a sales person or afiliated with massdiesel in any shape or form. Just trying to give my opinion.
Ron