Anyone? I don`t think that it`s really hard.

I wish I could answer but I only get exposure to customers who calls support so it doesn't represent the whole market.
I see many using Netapp or Microsoft target/initiator combinations but I am not knowledgeable enough to comment much more.
Maybe this question is best to be asked in a more storage solution oriented forums elsewhere...

If it`s a general question, then I`d preffer sowtware solution for SMB. It will save your money by using your existing network, what meens that you don`t need to purchse additional HDDs, wires, anything.

Thats good. I`ve googled for a while, and basing on this and answears, given to me on other communities I know that the most reliable vendors are StarWind, DataCore and Lefthand. Can someone tell something about them?

OK. Report:
I`ve tested all of vendors, and it seems like StarWind and Lefthand is the most reliable, but Lefthand is pretty expensive.
Thank you all.

 Microsoft released the new 2008 storage server that can act as an iSCSI target.  THus WIndows ease of use, and iSCSI target capabilities.  This is only sold on OEM systems from the likes of Dell and HP.  

Lefthand is quite a bit more expensive.

What something cheap, perhaps try freenas or open-e.  

After that, a Dell MD3000i is an inexpensive solution too.