New Project car alarm

[plumber]

Hello im new to this site

I have a motorhome which i want to build my own alarm .

I intend on using parking sensors placed around the side skirt to detect people coming close to the motorhome

i will do away with the buzzer and wire this to the headlights via a relay
the problem is what sort of relay do i need .

i want the headlights to come on flashing when the paking sensors start to detect at 1.5m pulsing bleeps

but then i want to have a voice siren also wired in to the buzzer which comes on when the pulse is continuous
i assume a different type of relay.

can anyone point me in the right direction with the sort of relays i need.

thankyou Tony