Try using some model rocket body tubes and premade balsa or plastic nose cones and glass them, it will save a lot of work. If the diameter is larger than 1.5" or so, you could even get some phenolic or composite tubes for additional rigidity.

Some sources to check:

http://www.balsamachining.com/

http://www.semroc.com/Store/Products/NoseCones.asp

http://www.apogeerockets.com/building_supplies.asp

Good luck!

Barry