Aye Up Gleams,
I would suggest that the first key issues in your question are the word 'kids', their ages and the lack of information in your question about how you intend to use the sets.
If your intention is to use the sets in a controlled, boundary'd, easily negotiable area with mature kids and/or accompanied by adults just for a bit of fun - pmr 446 might be all that it is worth paying out for.
If your intention is to allow the 'kids' to roam free range (unaccompanied/unsupervised) out in the sticks even in what appears to be a relatively small area, as some members have identified the .5w output of
legal pmr446 'walkie-talkies' can be
woefully inadequate not just in woodland but even in relatively lightly undulating terrain.
Add to that, depending on the age of the 'kids' the selection and the
re-selection of main channel and codes (on
digital pmrs) when they inadvertently knock them off the original settings can be not only daunting for them but lead to them going adrift of where you think that they might be (potentially without communications) - as a pair of youngsters that I found 'lost' and in despair in what is only a relatively small area of woodland during last summer discovered!
Furthermore, despite multi-channel and 'privacy' coding you might still pick-up morons transmitting garbage (and obscenities) over pmr446 which I'm sure that you wouldn't want to expose your 'kids' to.
I wouldn't recommend going down the 'hacked' illegal conversation of pmr446s.
The simplest, safest but not the cheapest route is low-end, 5w, professional hand held sets (licensed at £75/5 years) with click knobs to select on/off/volume and channels, far easier to explain, set and reset if they do inadvertently change the settings.
This of course is assuming that your 'kids' are old enough to learn a small amount of voice procedure and radio etiquette and discipline so as not to become a nuisance/hazard on those airwaves.
