To answer the "Which one is easier" question, most distributions of Linux are BY FAR, as Solaris is very picky when you're first installing and configuring it.
As far as Solaris goes, it is a true UNIX distribution, similar to but not Linux. Solaris is based on BSD. It's meant primarily for hardcore servers, supercomputers, and CAD/CAM workstations; it's also found use in graphics work. Solaris, like Linux and other forms of UNIX, can require some programming and command prompt skill, as you'll compile programs for it from time to time. However, it does have a GUI available, which does make it a suitable desktop productivity OS, albeit limited by available programs.
There are three versions of Solaris available for free on Sun's website - Solaris 9, Solaris 10, and OpenSolaris. There's really not much difference between the three versions. If you want the true Solaris environment and maximum compatibility with your hardware, I'd recommend Solaris 10. However, if open source is more important to you, OpenSolaris is the better choice.
One other thing that I can highly, highly recommend is that you want to learn the OS and have reference material (e.i. Google and the rest of the internet) close at hand, I'd recommend installing Solaris in a virtual machine instead of just directly on your hardware; as you get more familiar with the OS, you can install it directly on your machine. Sun is also nice enough to provide free training via online slide shows, so you can take a guided tour of how the OS works.