Dear ChewTopper,
If you are dead set for Toppers the way forward might be my Topaz Tres which is an excellent training boat for sailing a Cherub and available with trolley, trailer and Duo rig for a mere £1600.
Of course you could buy a '97 Rules Cherub for half that which would also make mincemeat of RS 400s like the '05 Rules in the video
(has Subtle Knife changed hands?)
Yes to 97 rules, or even a 91.
But please, please, please do not waste your time, money or energy on the topaz tres! If anything, this bathtub will totally dull any of the required ability needed to sail. Let alone train you for a Cherub.
Toppers a great in big swell and big breeze. I have good memories of surfing down big waves with the constant fear of death rolling at big open meetings!
I can thoroughly recommend a Laser 3000 (an early cherub decedent) as a trainer for you first Cherub. But you could just get a Cherub.