Appreciate that this may be completely dependent on budget but would be interested to hear what people are using?

I'm using a Sennheiser G2 kit. I love it, I've never had any issues once I've found a clear channel. I also have the SKP500 plug-on transmitter. It's awesome for making XLR mics wireless. I have never used anything more expensive like a Lectrosonics kit, the Sennheiser has been adequate for me.

Sennheiser G3 here. Works great.

ditto Sennheiser G2 kit

Are the G2 and G3 kits lapel mics or some kind of headset?

I take it this wireless mic is for your 7D? Plugging right into camera?

The actual type of mic is optional - they all did/do come with the option. Clip on mics are common for TV, headset mics can be good for some things - like theatrical shows where avoidance of feedback and being able to have loud PA levels is important. Headsets look horrible - so we use them because we have to. Visually, I'd rather have a conventional lav mic - but sometimes it just doesn't work. In video work, headset mics can work better if you have very high ambient noise levels in the room/location - so a commentator at a wrestling match or in the pit lane of a motor racing event benefit from the closeness of the mic, and you can forgive the growth on the face! The actual mic may well be a different brand to the radio system. Everyone seems to have their own favourites.