I personally have a Stanley plastic box with larger wheels on it with tool rolls for a semblance of FOD and tool control. This is probably the cheapest route, but occasionally you have to reorganize everything- it’s not as good as shadowing with foam, but it’s still effective.
I have a full tool set that permanently stays in the back of my truck since I’m a helicopter EMS base mechanic that has a 1 hour call out 24 hours/5 days a week. Generally, these are my cheaper tools that aren’t as valuable but it’s still probably over $3K worth.
A few guys at my company have went to the Milwaukee/Stanley/Craftsman “stacker” boxes that seem to work really well. I haven’t gone this direction since my box has to stay under my truck bed cover. It’d be great for someone that has an SUV. Another individual got a few Harbor Freight suitcase type boxes that have been shadowed. A few guys have knock off pelican cases that seem to work really well.
What kind of aircraft are you working on? Do you have a short call out response time as well? Are you flying on the airlines to the worksite?
One thing is for sure, check your company’s policy on replacing lost or stolen tools and have something in writing. Some require you to have a list or take pictures. If you don’t have documentation, and your tools are lost/stolen, you’re out of luck. I had a friend that had $10K worth of Snap-On tools stolen from his truck. Luckily, he had full documentation and was reimbursed every cent.