Mark's right...the three Epic offerings are more ball than you need for what you're looking for.

If you only want a 4 ball arsenal, go with the Epic Battle, the Horizon Pearl, the Venus, and the Spare tire.  A 5 ball arsenal would be more rounded, as you could get a solid reactive in there as well as the pearl reactive...for that, go with the RS-X if you can get your hands on it.  The Horizon Solid is powerful, and the Epic is even more so.  The RS-X is a bit weaker, and would allow less overlap between it and the Horizon Pearl.
--------------------
"For the money, for the glory, for the fun.  Mostly for the money."
-Smokey and the Bandit

With the Roto's, the core strength is a little different than you'd expect.  Each core determines where on the hook scale it should go, then the coverstocks they throw on there determine on what sub-part of the hook scale it should go.

The Saga is actually a touch weaker than the original Epic, despite the slightly stronger core.  Why?  That hybrid coverstock.  There is a ton of overlap between the two, but the Epic makes a harder move off the break.

As far as the planet lines, you need to define "dry".  Then take your planet ball.

The mid-range is something that can be touchy as well.  The Horizon's are both deceptively powerful.  However, if you can get a hold of an RS-X, you'd have something weaker in core, but similar in cover.  The RS-X is weaker than the Horizon Solid, but more powerful than any of the planets.

Hope this clarifies.
--------------------
"For the money, for the glory, for the fun.  Mostly for the money."
-Smokey and the Bandit