I'll second the 'consult an electrician' comment , but here's the deal ;
Replacing the breakers probably isnt required.
220 AC is provided by combining 2
phases of 110 VAC.The breaker in question will be a double pole unit , one for each phase , i.e. one will be a black wire , one will be a red wire....
Black (phase 1) and white (neutral) provide 110 VAC.
Red (phase 2) and white (neutral) provide 110 VAC.
Black ( phase 1) and red (phase 2) provide 220 VAC.
So essentially , the double pole breaker can provide you with 2 circuits of 110 VAC , but you will probably require some rewiring .
-------
As far as a 'multiple circuit power bar' goes :
Nope.