And do yourself a HUGE favor, when looking for a grease gun, do not get the long handle pump type. Look for one that has the pistol grip pump, meaning you can hold the grease gun in one hand and still pump it like a spray bottle, and use the other hand to keep the fitting securely held on the zerk so it does not pop off. Also do not get a solid grease tube, make sure it's a flexible rubber tube.
Mini gun is fine except the availability of cartridges. Stick with the standard size, grease is cheap anyway since you dont use a whole lot of it. Just means you wont have to go back for more for quite a while lol.