Waterlilies for small ponds is a small Advice section in July's The Garden RHS magazine.
Download the page here. Waterlilies for small ponds - The Garden July 2016
From those suggested in the dwarf section we have Nymphaea 'Aurora' and 'Pygmaea Helvola' available on the waterlilies page. We have 'Laydekeri Fulgens' (very like the 'Froebeli' illustrated) which is redder than the 'Laydekeri Lilacea' suggested and Nymphaea candida rather than the tetragona suggested but both are dwarf white waterlilies.
We also have a cerise pink with red leaf 'Yuh Ling' and a paler pink pygmy 'Pygmaea Rubra' which would both do well in the 10-25cm(4-10") depth of water over the top of the basket the plant is supplied in.
In the small waterlily section we have James Brydon available. In this size range we also have the white 'Marliacaea Albida' and pale pink 'Madame Wilfron Gonnere' which will suit the planting depth of 30-45cm(12-18") of water over the top of the basket the plant is supplied in.
The article gives great tips on how to look after your waterlilies and get the best flowering results (aquatic feed tabs) and how to keep the water in your pond or small container pond, tub or sink in as good condition as possible with regular tidying and removing of dead leaves.