I guess if they will go on the stock hangers without moving anything you might as well try the 3rd gen springs.  I'm sure they would have to ride a little better.

Here is what I've been working on for the front of my 1st gen to improve the ride there...



I am using one extra long thin leaf from a rear pack in the front spring pack and also a cheapo home made 1" lift shackle to create a little more uptravel without significantly stiffening the springs or adding much lift. I am still able to run the stock draglink and the torque rod with no bump steer. Altogether I've probably only lifted the front like 1.5".  I got a smokin' deal on some decent monotubes and added some of those daystar bump stops that go right on the shocks in the "soft" red variety.   

I must say, the daystar shock bumpers really improve the ride over smacking down on the hard rubber pyramid style bump stops.  You get a nice progressive bottoming out istead of that "1st gen feeling" we are so used to.  I still need to raise my upper shock mounts a bit.  They were set up for stock rear shocks and my new shocks are just a bit longer. I have about 1" more compression than the new shocks and bumpers allow so I will make the shock mount about 1" taller.  As an added bonus I am getting about 3-4 inches more down travel over stock, so the articulation is alot better and it sucks up the big potholes and drop offs way better too.

My goal is an improved ride with better trail performance without a real lift or any of the "real" parts, and to keep it cheap and stock looking.  I will be curious if your 3rd gen rear spring idea works, it might fit my build plan if it does.