My notebook has a "scroll wheel" space on the touchpad. I think all HP and Compaq ones have for several years.

As far as different version, there are always tradeoffs. If you don't care about having the latest and greatest of things then I actuall like 3.1 more than 3.4 (3.4 needed cheat codes for my notebook, 3.1 did not. 3.1 had a lot more games that were removed release by release to make space for things I didn't use. But 3.8 was a big improvement, no cheat codes needed again and several things that didn't work before now worked correctly including my Wireless NIC.