I heard that they are technically illegal to own in the UK
That is nonsense.
Just buy what looks best for the job.
This is hardly relevant but if you really wanted a CAA approved radio, there are (were) several models. I have the Icom
A22 which was CAA approved. At least I think it is the A22 - it does COM+VOR. These very occassionally come up on Ebay.
There is a nice American
radio which also does ILS, which might be a real lifesaver one day.