I thought I'd post my recent experiences with buying mouse hardware, because I would have appreciated the advice when I was looking.
In the past I've run Bluetooth mice because it means there's no requirement for a USB dongle on the computer. I've run a Microsoft Bluetooth Notebook Mouse 5000. It's small, and comes with a case for when my laptop goes home in my backpack. It's run well over the years. I like that it's got a thumb button for going back. Unfortunately I've had the odd time when it just doesn't connect for no apparent reason and I have to go through the motions of deleting its entry in "Devices and Printers" and then re-pairing it. Sometimes this is related to low battery charge, but not always.
So recently I've been looking for a new mouse. There's a plethora of new ones turning up in the market calling themselves "Touch" mouses. These often feature no buttons, but allow for gestures and multi-touch (either responding to the Apple Magic mouse, but more recently working towards Windows 8). I have trialled them in the past and the issue seems to be getting them to recognise a middle button click (used for panning). Transitioning to them could be tricky as if you rest your finger(s) on top of the mouse this might be seen as a gesture of some sort.
So, my recommendation is for something a bit more conventional. At some stage the gestures may be useful in CAD, but it seems a bit premature at this stage.
I tried a MS Wireless Mouse 3500. On the whole it was good, except the middle button click was really really really laggy. Panning in CAD became a big chore.
I tried a Logitech Zone Touch mouse T400. It uses a seperate touch pad instead of a wheel, which worked fine - It recognised the middle click. It used haptic feedback to replicate the wheel click, which felt a bit weird, and it didn't really provide the stop that a ratcheted wheel does.
I trialled a Logitech Anywhere Mouse M905. Fantastic mouse, really responsive, multiple progammable buttons. There's a case for the mouse included and there's a place inside the mouse to hide the USB dongle. Unfortunately the middle button click was not available in the wheel, but relied on you clicking a button just below the wheel. (clicking the wheel changes the wheel from ratcheted mode to un-ratcheted.)
I've ended up with a Logitech Wireless Performance MX 950. It's bigger than the 905, but the wheel behaves as the middle button (and a seperate button is used to disengage the ratchet). It's really responsive, and has multiple programmable buttons. Logitech haven't provided a case or a hidey hole for for the USB dongle. It comes with a single AA rechargeable battery, USB to micro-b usb cable for charging from your usb port, and a power socket to usb adapter, so there's multiple options for charging and you can always throw a standard AA into it.
I realise that I've stuck with only a couple of manufacturers, and I haven't gone looking at some of the more high end specialist mice.
HP Elitebook 8560w
Core i7-2820QM (2.3-3.4GHz)
nVidia Quadro 2000M 2GB
I use a logitech M325. Pretty small, great on battery life - at least a year without switching it off now. It has a space for the dongle under the battery cover, wheel acts as a button. No case though!