go with a viper800 if you're plannin on adding lots extra remote features. that's what i have. it gives you 7 channels to play with. most alarms will only have one or tow extra channels. right now i've got a trunk popper, window roll-down (validity output), auto-roll up upon arming, remote radio (latched output)... i'm prolly gonna put my loud ass Hella horns on another channel and possibly my headlights later when i get HID's again.

to do the window/sunroof roll-up you just use the ground when armed wire from the alarm to trigger a module which controls the windows and sunroof. they module is about $20 on ebay. you need it b/c it senses when the window/sunroof is fully closed (it senses the voltage spike) and cuts power to the motors. otherwise it'd be like holding down the window 'up' button in the car the entire time the alarm is armed... that's bad for the motors :P

when you don't want them to auto-roll up you would just bypass the signal from the alarm to the roll-up modules with your manual switch.

the solenoid for a trunk popper is about $20-30. easy to install just time consuming.

sry i don't have any info on keybads though.