Grimmlokk
Ahn'Qiraj Raider
This is what Gwar did with Oderus Urungus. Dave Brockie was buried and "Oderus" was Viking'd. Full costume etc put on board.To my mind, it doesn't need to contain the body anyways - it could be symbolic. Perhaps even SHOULD be.

Realistically? Get hammered with a bunch of friends and talk about them and cry. Unless that friend actually wanted some big spectacle made, this is really all for you. Drunken night in their honor will be cathartic for you. I know it was for me earlier this year when my mom died. Write something down too, in the same vein.