First thing you probably need is a Kwik Lift. A lot safer than jack stands and gets the car about 24 inches off of the floor, with plenty of room to maneuver underneath. Not real cheap at about $1k, but cheaper than a funeral.

As for calling someone in your house get a pair of small walkie talkies and leave one on in the house where it can be readily heard. If no one is home, take a cell phone with you when working under the car. I use a bluetooth phone with a bluetooth head set. I can just push a button on the ear unit and tell the phone who to call, without having to touch the phone. Phone does have to be within 30 feet of where you are.

As for creepers, Sears sells a couple with either inline wheels or covered wheels for less than $100.