Of the huge, long dumpsters you always see at construction sites:
20yard container is 4' tall
30yard container is 6' tall
40yard container is 8' tall
Just look in the phone book under waste disposal, call around and ask for quotes. Tell them you want an XX yard roll-off container, what are the current residential rates? Some only give you 10 days or so before they charge a daily rate to have it sitting at your house, ask about that.
They may want a CC number before they bring it, or be prepared to have a check for the driver when he sets it off, and there is always a possibility of them coming back and asking for an overweight charge if you fill it with lead or crap like bricks, be sure to ask about that.
Get twice the size you need, your asshole neighbors will fill the other half for you.