To clarify...
Whispering Giant,
156 seats is the maximum number that will fit in the 319. More seats, more bums, more cash.
As for the seat pitch, the seats that Airbus produce are so well ergonomically designed 28" feels bigger than 32". I challenge you to try it.
The 319 under an exemption can operate with 3 wagon dragons as long as it has the extra two self help exits fitted in the centre of the cabin. (Easyjet has succesfully applied for this exemption even with all 156 seats full)
The 737 300 can operate without restriction at SOU. However it was confirmed last week that a 319 was being sought on a damp lease basis to operate from SOU next summer. This would run along side the two 737's operating out of BHX.
My source? Would Shep tell you where he burried his bone?