I have a couple of tool bags in my truck. One's full of pellets, BB's, CO2 and .22 LR and the other's full of cleaning gear, lube, tools and hearing and eye protection. I also keep a CF tank and a hand pump, plus a Huben fill probe in my truck. That stuff pretty much lives there, so I've always got what I need with me for airgun shooting.
For transporting the guns the gear I've finally settled on are Harbor Freight Apache gun cases and gun socks. They're big, awkward and heavy, but they're also tough and waterproof and you can easily fit 2 guns in one with no risk of damaging them. When I've hauled milsurp PB's in them I've loaded them 4 to a case before. So with two cases I can load up 4-6 guns. I leave the pluckable foam intact as I don't want to have a special case for every gun I own. If you wait for specials they are frequently on sale for $120. I've got one of their large pistol cases as well and I can fit 6 pistols in it.
I've got a couple of Flambeau hard cases as well and those are nice for packing a single gun. They're much lighter and I picked them up for $30 each. Not as tough as the Apaches and I wouldn't want to carry two nice rifles in one case at the same time with one, but they're just easier to pack. I used to carry all my guns in those kinds of cheap hard cases, but what I found was that I often had four or more cases with me and that just took up too much space.