I run a year round camp…during the summer (3 months) we use two-way radios 12-16 hours per day. We have a license (for up to 2 channels) but I think we are better served by radios that don’t require the license (more channels, etc.). That being said, we’ve used Motorolas and Unidens (talkabout types) and they just cannot withstand the abuse we do to them. Long days, outdoor use, being dropped occasionally, etc. Batteries crap out on us, and they simply stop transmitting…
You might want to look at Icom radios. They really have surprised us with how durable they are. If you are too rough for a Motorola Talkabout, I doubt any consumer GMRS type radio will last for you. Even Midland radios are only a bit more rugged than Motorola Talkabouts.
Keep the license (It is against the law for you to use GMRS radios anyway, unless all of your staff are family members - though I think for a camp that should be wavered.) and look at low-end commercial grade UHF Icom or perhaps Kenwood radios with Li-ion batteries:
