I'm NOT familiar with the Rusty Springs. From your post it sounds like they will give 2" higher ride height?
The Blisteins 5100 front Strut/Shock has adjustable spring perches, the lowest level you can adjust it, will result in a 3/4" lift. So, add 3/4" on to the front springs height if you use them.
A longer spring means you'll sit higher, giving you more rebound, but not necessarily more jounce, you just swapping one for the other.
The rear axle can extend/jounce a lot more than the front, using the longer 5100 shock will get you more jounce. The front, perhaps the longer 5100 will get you a tiny bit more jounce, but since its an independent suspension you may have interference if it extends to far.
The real problem is going to be rebound, can the new longer spring and shock compress down to the same point as the shorter OEM spring and shock. If they can't, then they will be damaged going over big bumps. That is why kits often come with modifications for Bump Stops, to increase them, so they stop the suspension from rebounding to the point they damage things.
That's sorta why the best way to do a lift is with a good kit, that was engineered and has everything you need.