18 ga good for most projects. Husband says 16 ga is for nailing thick casing and baseboard, to go through wood, sheetrock and to stud, using 2.5 inch nail. 18 ga is good for 2 inch nail, and nothing longer. And nails are cheaper - box of 1000 will last forever for normal home use.
Fabulous price for 18 ga, go for it.