Re the Logitech trackball - the models do vary, one I used had a button to select 'scroll' (then use ball to scroll). I don't recall now if that was a default function, or if I programmed it using the Logitech control panel.
In CAD, Pan & Rotate/Orbit are usually selectable from menu/toolbar - so if you have spare buttons available it should be possible to configure these to allow you to quickly change function without taking hand off the trackball.
Any reasonable quality mouse with scroll wheel will get you going - typically using combinations of the 3 buttons you can momentarily change 'mode' of the mouse to either pan or rotate.
3Dconnexion (now Logitech I think) devices are a useful extra for CAD, they don't take the place of a mouse. I have one, but most of the time I just use the ordinary mouse unless manipulating the CAD model is very awkward.