Which size turbo?

[APacitti]

I've tried to search for answers to these question but I've come up short so here i am. My truck has all the mods that are in my sig, however very soon it should have a fuel system and a smarty in the place of the hot juice. I'm looking to purchase a single turbo, i tow single vehicles/boats (<9000lbs) fairly often so towing manners are important. From what i've read it looks like i would be better off with a smaller turbo like a 62/12 and my question is if i could get away with a bigger turbo like a 62/14 or 64/something and would that provided much of a benefit? Also i've been looking hard into various turbo companies and i'm a little confused as to what the real world differences between the industrial injection turbos are? (phat shaft, super phat shaft and silver series). Basically i'm looking for a turbo that will help make use of my fueling and reduce egt's, i'm not looking to build a race truck. I will most likely add some small injectors and cam in the near future however that will be about it in theory. I"m looking more for size suggestions than brand preferences.

Thanks