Personally, I love landscapes and beach scenes. I also like florals...I especially like hydrangeas.
Not a lot of luck, but here's a couple of semi related sources with a (modern) painting of an English slave and a contemporary portrait of a slave ship out of Bristol. The third has some paintings of black people in England (not Bristol specifically)...
hmm...i hope that u do know todays paintings cant beat the paintings done by the masters in those days...however, if you need some pointers for the debate, maybe you could use these points...but, im sure they are not very strong to oppose against the...