Your choice depends on what your goal is. If your goal is to have a long gun and a pistol that use the same ammo (and spares of both) take option #1. If your goal is to have semi-automatic rifle with greater range and a sidearm, take option #2.
Although I like the PS90 and it's neat to have your pistol and rifle use the same ammo, I think the FS2000 can do everything the PS90 can do and more. I do not mean this as any disrespect to the PS90 owners but you have to look at what the original idea was behind the P90. It was the Personal Defense Weapon concept for those who didn't need a full rifle (i.e. vehicle drivers, artillery crews, rear echelon personnel, etc). The PS90 is the compromise for the American civilian market where the body armor piercing ammo was restricted, the select fire feature was deleted, and the firearm got a very long barrel which undid a lot of the original P90's compactness. Basically, it is not a PDW anymore. The PS90 is very enjoyable to shoot and it will absolutely cause damage to a person (if needed to), but it lost a lot of its advantages when the P90 was transformed into the PS90. Additionally, if you shoot gun games (i.e. 3 gun) a lot of people calibrate the plates so that they will not fall when struck by the 5.7x28 round. That is annoying and led a shooting friend of mine to sell his.
In contrast, the FS2000 does not face the ammo issue that the PS90 faces and it uses common mags. Its barrel is only a few inches longer than its F2000 counterpart. Of course the select fire is also a deleted feature in the FS2000, but on balance I feel the FS2000 is less of a compromise than what the PS90 is.
That said, you have to weigh what is important to you and make a choice on your criteria not mine. -At some point, I'd like to get a PS90. My delay has been that I can't justify the cost to myself given that the FS2000 is a solid platform that has greater range.