rolled on paint will pick up the dust just the same as sprayed on paint. The HVLP Sprayer helps because it shoots the paint to the surface instead of sprayers which mist the air and the paint falls.
Time for a ghetto spray booth ( like the one linked to on the honda site ) with some tarps or even cheaper get a roll of vapour barrier. Mist down the walls of the booth ( not the ceiling though ) and totally soak the floor with a hose before you roll the car in ( that will help to keep the dust down ). Tack off the car with paint thinner before you paint and off you go. Always do your bodywork outside and away from the area you will use as a spray booth so the sanding dust does not kick up and ruin your paint.
I am not a painter by any means but I grew up around a backyard mechanic and learned a lot watching him "clean-up" and re-sell cars we would pull in for scrap. He would take the motor from one, trans from another, some wheels he saved from another crap car with good tires and then if it needed it he would paint a vehicle in the middle of his 2 car garage stacked on both sides with motors and parts he would save. With this method they would turn out very good ( for a driver ). He always said to use solid and bright colour paints ( white, yellow, tan, blue ) to help hide the shoddy bodywork and any sports where the paint was dry or too thin. Really kinda miss having him around as he was a wealth of self taught knowledge.