Medium business file server

Hello fellows, this is my first time i assemble such a server, so i rely on your help! I need a file server for 200-250 users which will run FreeNAS software with 6X 2TB SATA2/SATA3 HDD in RAID 1 array.
Can you suggest me Intel motherboard that can handle 200-250 users???
My biggest concern is abilities hardware to provide sufficient performance for 200-250 simultaneously connected remote users.

are you building from scratch? The issue you have will be your network bandwidth as you already stated you drives will be on a nas and not on the server you are creating. The server would handle logins and maybe permissions but not directly be tied to the disk access portion of the storage... This makes the job of the server very easy and you could even use a desktop for this use.

Thent

still i hesitate about motherboard, which one to buy!? i was recommended SuperMirco, and i like this choice, but there are some problems with buying SuperMicro motherboards in Europe.
So can you give me some suggestions about choosing motherboards? maybe some examples?

If you need to support 200+ users then your looking at 1Gbps+ on network access and at those speeds your better off getting a system with a warranty and support vs a roll-your-own.

Also supporting multiple specs like SATA 2 and SATA 3 drives is generally not considered a good practice because of MTBF issues with mixing and matching drives will lower the lifespan overall and raise the chance of lost data.

How much data do you need to store and how many concurrent users do you need to support?

Are you also looking at speed or data integrity as more important?

-Splints