Cold Steel is the most versatile, but not the lightest. If you can accept the weight, it's really the best value to do everything you need plus serve as an axe, machete, paddle, etc. Tubular handled trowels are not a bad option. You can just pack them without a handle and add one to the length require for leverage and digging as needed. I have experimented with the titanium version:
Titanium Trowel
It works quite well in softer soils, but the soft titanium doesn't work well at all in hard, compacted or rocky soils. For most soil types around here, the worst is the harder Georgia clay, but the top soil is pretty easy to work when digging cat holes, tubers, or shelter drainage ditches. I cut and punched out the pin and secured a wood screw in the handle for packing. I just use it as a hand trowel or trim down a sapling to make a longer handle as needed. I do like a metal trowel if I'm using an open fire and coals for cooking; they make it far easier to maneuver hot coals.
The heavier CS shovel is a weapon in it's own right and could also have the handle removed for packing and one added later as needed. I keep a CS shovel in my primitive kit; the versatility as a tool is worth it's weight if I'm in need of significant shelter building, foraging and excavation.
ROCK6