eyefinity monitor questions

Evening all,as title really,I understand that you need at least one of the monitors to be connected via display port ,but does it matter if the monitors are different sizes.As in 2x22" either side, and a 24" for the center?Iv'e allready got an asus 22" and am looking to get another, and this for the center,Dell u2412m widescreen ipsOr would it make more sense to get 2 more of my current monitor and the active display port to hdmi/dvi.Either way it works out be roughly the same price.(I can't remember the monitor model number off hand)My GPU is a saphire hd 7850,soon be 2 in crossfire

Yes mate that was the only thing I could realy be sure of,but i cant help thinking would just over an inch make much of a difference.(going on exact sizes ov the mentioned monitors)

Iv'e just been checking out some youtube vids and your right it makes a whole load of difference,their was one guy where there was less than an inch and it looked awfull.As far as the active dp to hdmi/dvi,ive been searching www land a some people say you can use the mac adapter,and some say it is unstable,can you shed any light on this subject?