Hi! The I/O modules you listed are of "compactFieldPoint" family, except the FP-1601, which is "FieldPoint" They're two different families, and if you want to build a (newer) cFP system you can't use a FP-1601, while you can use a cFP-2120 (for example). This module has the same role than FP-1601 (even if they're different), it is called an "ethernet interface module", and there're different kinds, all compatible with cFP I/O modules you mentioned.
All cFP-21xx (cFP-2100, cFP-2110 and cFP-2100) have ethernet port for connection with your PC, the difference is in the number of serial ports and internal RAM of the controller. If you think you can be done with 64 MB of RAM and one RS232 port, a cFP-2100 will do that.
My personal suggestion is to use a cFP-2120, the top controller, because you get 128 MB of RAM and 3 RS-232 ports, and one RS-485. That can be useful for interconnecting to some other system....
I don't know in detail all I/O modules, but I think you need a connector block for each one.... anyway, you can ask directly to NI about your complete configuration, they'll tell you.
Usually, ONE power supply is enough for all the system, just check Watts you need! At labs, I use a common 24 Volt PSU (SMPS), 75 watts, but, this may vary upon your power consumption needs!
You didn't mentioned, but you need also a backplane!