If you have specific wishes, they really need to be planned, discussed, and documented in advance. When my sister was diagnosed with cancer, she not only had a will, but put together a list of personal wishes she made up for just us, such as a memorial service vs. a funeral and certain music played. All of us, including her three daughters, were well aware of what they were and planned to carry them out.
What we didn’t know was about all the details involved in ensuring that they got carried out. While her body did go to research at her preferred medical school, despite being slightly under their conditions weight-wise, and while the remains were cremated, we did not get the ashes back as assured by the parties involved. Her daughters were upset, but have learned to move on.
Some of you might also be interested in this Fluther thread There are some interesting and creative ideas on what some Jellies would like to happen.
The bottom line is, make some type of arrangement while you are alive. Too many loved ones have been saddled with hefty expenses of a coffin and funeral service because there were no instructions and dealt with it based upon their own preferences.