I wouldn't pay into a funeral plan but you could open a savings account just for your funeral. Some of the banks have regular savings accounts which pay more interest if you are prepared to "lock it away" for a certain number of years. I remember reading in a financial paper a little while ago that these funeral plans are not good value for money.
Not morbid at all, merely being practical. I have made a will setting out my wishes and even a guideline for my funeral service, I have also signed a Power of Attorney just in case I lose my marbles - which on current form should be some time next week 