Which set would be best for getting out farther?

If the best you can do is a 3:1 SWR, then there is something wrong with your antenna installation. Most likely the problem is a poor ground at the antenna.

As for performance, the rule of thumb is the bigger the antenna, the bigger the signal.

 

-"dyslexic"-

 

Algebra claims another victim. first is left equals right the they keep whating you to know Y...... and next thing you know, 1.3 becomes 3 to 1

 

You ask about a "set" (I assume you mean pair?) but, say you ran "a" coax to a wilson/firestik. <--- the coax is different 50 ohm vs. 75 ohm.

Running your own I'd suggest a single ant. w/ RG8x
The best antenna is the one that can survive your abuse, while making it as long and tall as possible. <--- I'm no ham, but this is what I was taught.
The fiberglass whip is great for top load making it more desirable, however tree limbs will quickly muck it up.
The loaded ant's like wilson2k don't get the "load" as high, but it is good around low clearance's for the abuse it will take.

 

In theory, yes the firestik should get you out further for its top loaded design.

 

No it won't make a lot of difference when you come down to it.

What does is a lack of signals on the channel.