Let's see, you are looking for the
HMS Aurora, an Arethusa Class Cruiser
Sister ships Arethusa, Galatea, and Penelope.
Long Link here( cut and paste the whole thing if you have to)
http://www.whiteensignmodels.com/acatalog/index.html?http%3A//www.whiteensignmodels.com/acatalog/Online_Catalogue_1_700_Scale_Waterline_Ship_Kits_15.html&CatalogBody
Not cheap
http://www.sandlehobbies.com/resinkits/wem/700/penelope1700.html
And the Spartan,
A Bellona Class Cruiser
Sister Ships Bellona, Black Prince, Diadem, and Royalist.
I can't seem to find any info for models of this class, but a lot of links group it into the
"Dido Class". If they are similar enough, you may be able to modify a Dido Class Cruiser to match the configuration of the Bellona class.
Good luck on finding a model.