Sorry for the late reply to this. Figured I'd post this in in case someone needs help in the future.
You can set specify the isolation level when you create your Server instance.
Make sure you have the following references:
using Microsoft.SqlServer.Management.Smo;
using Microsoft.SqlServer.ConnectionInfo;
And then set the isolation level when creating the connection
Server theSQLServer = new Server(@"cb-z420vmsasq1\sql12");
theSQLServer.ConnectionContext.SqlConnectionObject.BeginTransaction(System.Data.IsolationLevel.ReadUncommitted);
You may have to change this for different transactions.