Which plants please?

Hi everyone,

I finally finished my pond on Sunday (my first one ever) its stats are as
follows :-

1000 litres (approx 220 UK gals) preformed pond
Aquamax 3500 pump
Hozelock Bioforce 1100 filter
Waterfall

I am off to buy plants this coming Sunday and unfortunately I am the sort of
person that will buy whatever the salesman tells me to buy. I've been
reading some of your posts over the last few weeks and wondered if you would
please give me some tips on the plants I need to buy also there are a few
posts about snails but although there was mention of people having bad
experiences with them they didn't go into detail -should I get some or steer
clear?

I only intend to keep small goldfish (is 5 about right) because I'm hoping
that frogs and newts will come to my pond in their own time.

Also please could you clarify if my filter is a bio-filter like the ones you
guys talk about or if the fact that mine has the word bio in the name is
just misleading.

Any hints and tips about how to look after my pond and what else I need to
buy for it would be very very appreciated.

Many thanks,
Jay