Just looking at ordering one of these, can someone tell me if rechargeable batteries fit in to the unit ok ?

I have lots of rechargeable batteries but in the past certain items have been difficult to fit the batteries into, as the batteries tend to be a bit thicker with the outer plastic layer.

Cheres

It takes 18650 batteries & they fit fine – even the protected ones

It wont take standard AA or AAA batteries. As Upling said, You will need 18650 ones and a charger and probably a UK plug adapter as well for the charger.

All in it will cost a bit more. If You want to run Your AA than get a Ultrafire C3 Q5. Uses 2 normal AA's, rechargeable fit fine and if You get the extension You can run the torch at 3xAA's (but only with rechargeable as they run lower voltage) and it spits out close to 200 lumen which is pretty good. The P7 is much much brighter but for general use the C3 is fine and it would make a good helmet light as it's pretty light.

Get the five mode one!
Low on the 2 mode version is too low to be of any use, the 5 mode might be a 'little' more hassle but it's more useable.

Again never had any problems using/fitting the 18650 batteries into them, though we all bought the TrustFire Protected 18650 2500mAh Batteries