tool box recommendations, or, rear seat alternatives

i joined this forum a few years ago because i bought a new at the time 2011. i only had it for about a year and a half but apparently my dad liked the truck and years later, finally bought his own, a '17 sr5 4x4 auto in barcelona red.

anyway, he's pretty old school (and old - he's almost 80) and always puts a bulky tool box in his bed. this truck is the smallest he's had in years so i think he'd be happier with a smaller, more modern tool box.

i searched a bit but wanted to check in and see what you have/recommend.

i also suggested to him since he doesn't really need all of his stuff in the truck like he used to, he may consider keeping some stuff in the back, in the cab. he said he would want some sort of dog seat protector to catch any crap that could come off of his gear. so, anyone have one of those that they really like?

so far i have for him Aries mats (loyal 3D/Aries mats customer here) and a set of AMP Power Steps, so my mom can get in the thing.