I have to say something from the bottom from my heart:
FUCK TECH.
If you want to make an apocalyptic scenery that is kinda in the future, than dump the fancy lightning guns, big laser tanks and super-duper planes. No, if you want to do it the good way, then go towards the Fallout/Mad Max/STALKER/Other direction. Make the struggle for surviving worthwhile. Let them rediscover technology like combines, halftrack jeeps and armoured schoolbusses. Give them weaponry like improvised tools or rusted bolt-action and held together with duct tape rifles.
I always wanted to try out something new, not something high-tech. Just.. new things.
Ok?