It depends on what you have and need. If you plan to create new random variations of flowers or create wind animation, you should take the GrowFX version. If you can work with static models, you can choose the 3Ds Max version. In any case, all of the static models files of the 3Ds Max version also ALSO included in the GrowFX version. Choosing the GrowFX version will give you EVERYTHING from the 3Ds Max version PLUS the GrowFX files.

No, you don´t NEED to own GrowFX to use Real Flowers. The 3Ds Max version (not the GrowFX version) has static models, while the GrowFX version includes each flower as 3ds Max scene with GrowFX as model source. Using GrowFX will enable you to create more random variations of each flower, animate growth or wind.

Well, yes and no. If you want to create flower beds, like the ones included in this product, then YES, you should consider Forest Pack Pro from iToosoft, because it´s the most advanced scattering plugin for 3Ds Max on the market. There are alternatives for scattering, like Multiscatter, or even the integrated Particle Flow together with the new vray instancer feature in vray 3.0 or Corona scatter within Corona itself. But the easiest and fastest solution to create large scale flower fields with many flowers really is Forest Pack Pro.
NO, you don´t need Forest Pack Pro, if you want to place flowers individually in your scene, in a garden, on a street or other defined places which do not require hundreds or thousands of f.

Yes, the GrowFX version includes EVERYTHING from the 3Ds Max version PLUS the GrowFX scene files for each single flower.

The installation is easy, as you only need to copy one folder from the download in your Forest Pack Pro user library. The installation is described in a short instruction textfile that can be found inside of the Forest Pack Pro folder from the download.