Waka Flocka & Gucci Mane — Footing GIANT Funeral Bill for Murdered Slim Dunkin

Waka Flocka Flame and Gucci Mane are throwing down big $$$ to cover funeral expenses for a fellow Atlanta rapper — who was brutally gunned down last week — lavishing their fallen comrade with elaborate memorial arrangements.

Rapper Slim Dunkin (center) — real name Mario Hamilton — was shot and killed Friday night inside an Atlanta recording studio … after a verbal altercation with an unidentified man turned deadly.

Now, a rep for Waka and Gucci tells TMZ, the rappers are pooling their assets to ensure Slim is laid to rest in the best way possible … with an elaborate funeral that includes a white horse-drawn carriage, massive white floral arrangements, and a white dove release ceremony.

We’re told Slim’s family will cover some funeral costs — but Waka and Gucci are paying for the lion’s share.

The funeral is scheduled to take place Friday morning at 11am at Berean Christian Church in Atlanta.