Just measure between the inside of the rear dropouts and you'll have your hub question answered in a flash. If it is 120mm you might not want to go to 130mm.
Modern tubs like the Continental Gatorskin are very durable and you can put some latex in them to give a bit of extra puncture protection. I wouldn't use Caffe latex though as all it seems to do is spray the frame with brown goo.
Continental make a decent latex, but I don't think you can get that in the UK and there's Stans too.