L -
Lets think about this logically...
First, you didn't mention the type of bow.
The following is true for ILF type rigs, and generally true for anything else. Just to many "customs" out there to make blanket statements.
There are so few "bad" limbs out there, that unless you buy the wrong length or weight, anything you get will out shoot you for a good while, possibly forever.
When you reach a point that you want "higher end" limbs, it will usually be more a matter or personal preference than anything else.
With risers, things are a little different.
First, the riser IS the looks of the bow, and if you think that dioesn't matter, you're kidding yourself.
Next would be the grip. Unless interchangeable, a bad grip (for you) will kill your shooting experience.
After that might be specific features you want/need in a riser.
But there's a catch...
If you're a new shooter, or new to a certain type of shooting, you really don't know what you want - even if you think you do.
That's why I always recommend a fairly generic set up for starters.
After a while, you can "upgrade" more intelligently.
So, the riser is the most important, but you have to know enough to make a good call.
Viper1 out.