hey man, i totally know what your talking about.
I had my hyundai coupe for 2 days and the next morning i went outside and someone had run over my car, 2 dents in the roof and 1 in the bonnet.
I think you should buy the same aerial, but this time wire the f***er up to your 12v battery. You will find the little bas*ard laying on the floor next to your car the next morning, trust me.
As as far as getting a whip aerial, i know a few people who have had problems because of the motor that pushes the aerial up. I think they ended up disabling it in some way before installing the whip one. Not much help i know but i think you should go with option A.
Im concidering getting one of those Indian alarm that shoots fire out from all sides of the car if someone even gets close to it..... But mabye thats not legal in the UK.....Suits me just fine as long as i remember to disable it before trying to get in it!!!!!!!!