power window and door lock relay

Both the door lock and window work the same way so i can use 2 of the same relay, but i need to know what kind of relay I need and how to hook it up as I'm pretty clueless to this kind of stuff. 

I have 2  wires for the door lock and 2 for the window motor...one wire has to be grounded while the other has power for it to open/unlock, then u ground the wire that had the power to it and put the power to the wire that was grounded to close/lock.  I want to hood up 4 push botton switches (2 for the lock and 2 for the window) one that locks/opens and one that unlocks/closes.

Do i just need a simple 4 prong relay or a 5 prong (or do i need something totally different)  I have a 4 prong (85, 86, 87, 30) and Ive used 5 prongs (85, 86, 87, 87a, 30)  I'm slowly learning how to use relays, but i was hoping that i could get some help cause its for a camaro that I'm working on and its supposed to be done in a week or 2 (have to do bodywork and paint too, so i dont want to have things that take too much time)  I would greatly appreciate any help with this situation.  Thanks.

Allright i just have to verify that i'm understanding this right.

this is the diagram.

The wires that go to the actuators are the wires that go the the lock and windows.  Do I add the switch between the wires that say - alarm(-) lock output/ input?  and both would be ground wires going to the switches right?  Thanks again for helping...i believe this is right but i dont want to fry a relay (cost me 7-8 bucks a piece)