Glassing on wire might not be a bad idea, but you'll have to be sure that it holds its shape nicely. Besides, as Saby also suggested, I assume it will be hell to have a regular, correct, balanced, bump-free, whatever... shape.
Attach some polyethylene-plastic on the inside, nicely taped at the outside.
Then lay-up your fibres and glass it on the outside. The plastic will prevent excessive dripping (and waste of polyesther) and most probably easier to wet the fibres the right way. Leave the tape, it wont matter.
Once the first layer has dried, you may do the inside if you want to use the wire for extra strength.
But why would you do it? Quick? Easy? Cheap?
IMHO, if you want to glass it, there is no such way. There is just, not so cheap, expensive and really expensive. Or not so quick, slow, and really sluggish....
Ok, whatever... if you want it quick and easy, build a square box. If you want to use fibresglass, take just that little bit more time.
Foam is the way to go if you really like shaping, yet a bit dusty. But you can make any possible shape. I used to make a 2m wwkayak this way. Use a router for the big rough shaping, the surform rasp for smaller shaping.
If you want extra strength, use 3mm-ply, it's easy to work with, easy to measure, easy to saw, bend, stich & glue. If you still want special forms, glue some foam on your wooden frame, and you can still shape special parts.
And if you don't want it all inside your fibre, you can always try to put some plastic on your wooden pod, before laying up the stuff and remove the wood afterwards.
