The Question and Answer section for The Adventures of Huckleberry Finn is a great resource to ask questions, find answers, and discuss the novel.
Huck actually feels badly about what happened to the two conmen even though they really had it coming to them.
Tom wants a drawn out, rather ridiculous plan, to rescue Jim. Tom is not interested in rescuing Jim more than orchestrating an adventure. He wants bragging rights to a convoluted plan that is not practical in the least.
Huck never felt that Tom had any sympathy for escaped slaves or blacks in general. Tom was mainly interested in the challenge of getting Jim out.