Regardless of whether you get the 3-way Mongoose M80G or Viper 855XV (or any other, which conform to AS), certain options will be on offer.
a) remote boot release - I'd decline due to likelihood of cable stretch
b) automatic door lock upon start-up - I'd accept if there's a chance of carjacking in areas you'd park or drive
c) auxiliary circuits eg. for turbo timer and others.
The alarm box itself though, you may prefer to ask the installer to place it in an obscure position.