I personally had a Clifford G5 650 fitted its nice and loud and has warn away etc...was not that cheep and i did have auto window closers added.....the main pain is o have 2 remotes as the fitter could not make the clifford work the ford double lock so i have to set the ford then the clifford and unset in reverse which i often get wring and the clifford goes off.
There are fitters out there that have worked out the double lociking but not many of them! i belive the toad is a good value system with good protection.
If you mess with the ford sounder it will invalidate its CAT1 class unfortunatly which is mad when u are making it better but hey thems the rules with CAT1 systems!