I will let someone else comment on float plane schools ....
is my UK license recognised according to CA CAA regulations?
One way to do this, is
1) do a Canadian medical (costs around cdn$120)
2) write the PSTAR written test at any Canadian Flight School (FTU) - I inviligate these for free.
3) get an Authorized Person to examine your certified logbook and ensure that your flight time meets or exceeds the minimum experience requirements for a Canadian PPL (see CARs) - I do this for free.
4) get one passport photo taken for the Canadian licence booklet (cdn$11)
Then the AP fills out the form and the application for a licence booklet, writes out a cheque for Cdn$55 payable to the Receiver General for Canada, and the package is mailed off to Transport Canada Aviation. A month or two later, you get your Canadian Private Pilot Licence Booklet (including medical certificate) mailed to you.
I have done lots of these. The resulting Canadian PPL is just like everyone else's except that it is annotated "issued on the basis of a foreign licence" which doesn't mean anything to you. You can get ratings and endorsements on it - night, multi, float, instrument - just like everyone else.
Note that you must keep the Canuck medical valid to exercise the privileges of the Canadian PPL.
The only problem with the above is that it takes time. In the long run, it's probably a better way to do it, but ... there are other temporary validations of your foreign ICAO PPL that Transport Canada Aviation can do.