I use Specialized tubes as that's what my LBS supplies (at not a particularly cheap price). I wanted to pay less so found some conti tubes on ebay at a great price. I have a feeling they're only a great price because this particular bunch of tubes were defective (I had a problem with most of them). So I just stick with Specialized tubes from LBS until I an find something cheaper and just as good. Cant remember the exact sie of tube, but it's the one that fits into 23mm tires. I have no preference between long and regular stem (typcially i just buy the regular stem). Never had a problem with them apart from bad installation (which is my fault).