1. determine your total load. I can't imagine needing the full sized back packer/rollers for touring but I could for grocery shopping. The front packers/rollers are barely big enough for grocery shopping. I've got Orange pvc classic front rollers, gray plus front rollers and packers. I prefer the Plus fabric for the Rollers because it's easier to roll.

2. the more expensive model is only worth it if you want it and have the money. If you don't have a preference it's irrelevant.

3. you can't overstuff Rollers and get waterproofness but you can fill them up and clip the top leaving it open, with packers you can fill them up and then some more and still have the top covered for rain.

4. brown doesn't sound good but I'm no judge of fashion.

5. I regularly use some kind of cloth grocery bag liner for carrying tools so the interior doesn't get worn by sharp objects (or corners of six-packs of beer) or foam pad/inflatable seat pad for carrying laptop. I've had dry bags made of similar materials as the Ortliebs used for kayaking and it's possible to puncture them through misuse/abuse so I'd just as soon make sure they last awhile.