Can I inplment clustering with just 2 servers and one NAS ?

Hi, I have the following architecture, it consists in only 2 servers, connected to a NAS. ![architecture][1] [1]: http://ask.sqlservercentral.com//upfiles/arch.gif I'm having trouble in implementing clustering because I can't have a domain controller in any of them (if I do the sql server complains...). Is there a way to implement clustering with these limitations?