HI
Speaking specifically about your UK use.
Id really recommend you hire kit in the UK. We have recently switched to channel 38 from 69 here, and although there are still VERY limited (4) bands of free use in ch 70 they are VERY congested with every mobile disco and keep fit class. If youre doing something of even tiny importance, id remove yourself from the likelyhood that it will already be taken by an amateur, or overridden with intereference. Ch 69 will work up until the end of the Olympics, and is then given over to mobile broadband, where it this will swamp and radio mic out of the sky (and likely take ch 70 with it so is the rumour)
So ch 38 is where you need to be from now on in the uK, and this is regulated by JFMG. They charge £70 per mic license. If you hire from a broadcast kit hire outfit, it will already be licensed for you.
You can buy ch 38 kit and use illegally it without a license, but if youre shooting say in London where there is v high radio use, and youre on a licensed users frequency, dont be surprised if JFMG officers turn up and confiscate your kit.
Just hire, or hire a sound recordist here who will have the necessary licenses (hopefully)
Peter
Post Production Dubbing Mixer