Let me echo all the statements about Lear 25 from XtremePrototypes.
It's an amazing addon, really. The systems are all there, the AP works in a realistic manner, flight handling seems good and the visuals are actually top notch. If you don't like /A flying, installing a GTN750 into that thing is a breeze and changes the way you fly it to something more up to date.
Now, with Carenado, and especially their G1000, the woes don't end with avionics.
Usually, AP is really, really wonky. IAS climb is completely unreliable in most of their jets. Sometimes they deviate from the LNAV route too, which is a bit annoying.
And don't get me started on the engines. A lot of their stuff just refuses to climb into proper altitudes.
The best one from their lineup, assuming you don't want to go with Mr. Pieke's mods, would be CJ2.
So personally I would recommend two routes:
A) If you can live with gauges - XtremePrototypes Lear 25D is your best bet.
B) If you want modern avionics like G1000, go with Flight1 Mustang. It's amazingly good too. The downside with that one is that P3D v4 patch is not ready and I am not sure if planned updates to their G1000 funcionality will find their way to P3D v3 version.
Anyhow, all the best in your flying :)