Well first of all I'm not a big fan of the idea of a break and jump cue all-in-one since they are quite a bit different.
More professional players use the Predator BK-2 than any other break cue. I LOVE this cue and break considerably better with this cue than anything else I have had in my hands.
As far as jump cues go, this has been a recent thread on here that I posted in. Personally I like the Jacoby jump cue that Koinnikid is selling for $100 with the G10 tip. A lot of other players seem to really like this cue. The predator air is liked by some players although I think its complete crap personally. Also, the steve lomax jump cues seem to be in high demand as well.
More importantly is to ask yourself what is important to you in each one and break it down that way.
For example, do you want a leather tip or a non-leather tip on your break cue? A leather tip will be better for things like 2nd and 3rd ball breaks in 8-ball. The G10 glass tip (white diamond and similar) is very good all around. Its a harder material than phenolic reason, but holds chalk better. Some people might argue that it damages the cueball; however frankly I just don't seem to care if it damages the equipment since my break isn't quite that earth shattering in comparison to some players. The most popular right now seems to be the phenolic tip/ferrule combo in a moderately shaped configuration. Most people use this for both 9-ball and 8-ball "english" breaks (the 2nd and 3rd ball breaks) although most people I observe doing this are not doing it effectively in 8-ball. As a result of this I find that either a BK-2, which just hits the ball hard with a lot of control and still has the ability to apply english or a cue with a G10 tip or tip/ferrule has the best overall effect if I could only have one cue to use. As a closing note, you definitely want to investigate the taper on the cue before you buy it. A lot of cuemakers are using a very aggressive taper on break cues that makes the cue not move easily through your hands because it fattens up so quickly. This is why I like the laminated shaft on the Bk2, its plenty stiff without being like a log in my hand (yes I'm waiting for the jokes to start flying). Remember, everyone is breaking with a light cue now (18oz or less), this is not bowling.
As far as jump cues go, consider the same options however you probably want something with a little more shape on the tip so you can move around with english. Thats why I like the jacoby with the G10 tip and brass ferrule with a slight shape to the tip. I can draw the ball etc. Obviously lighter is going to be better here. Also consider finger grips etc that make using the "dart stroke" much eacher for really close jumps.
If I were making a short list of cues to try
Jump cues:
Jacoby jumper with G10 tip
Predator Air - people seem to love this thing
X-breaker jump cue - lots of people love this however I do not.
Break cues:
Predator Bk2 - its the #1 cue on the mens tour for a reason
Varney - I own one but am sorely let down. A lot of people on this board seem to really like them. I'm taking some weight out of mine and we'll see
X-breaker - people love this cue
Sledgehammer - the oldest jump/break of the "new style" of break/jump cues. A lot of people still use these.
If I were picking simply based on value...
The Jacoby jump cue is so good it cannot be beaten in my opinion for the money. It outperforms everything by a wide margin that I've used.
The J&J jump/break cues that are available are actually quite good for the money. Switch out the existing ferrule and tip for G10 and shape it slightly and you will be VERY impressed for less than $100 for a jump/break cue.
I'll shut up now.