[SalesForce] How to display 1 out of 2 possible fields values in same column : visual force

I have a column that needs to display date if there is no condition else display a combination of text+date if a criteria is met.

I have to append a text Week Of to a date field if a custom field material_group__c in Object1 has certain values N2, A. I want to achieve this only using VISUALFORCE.

Following is what I tried…

ATTEMPT 1

                   <apex:column title="Estimated Delivery Date at time of Order" rendered="{!OR(p.gew_material_group__c = 'N2', p.material_group__c = 'A')}">
                     <apex:facet name="header">EDD</apex:facet>              
                     <apex:outputText value="Week Of- {0,date,dd/MM/yyyy}" > 
                        <apex:param value="{!p.planned_ship_date__c}"/> 
                     </apex:outputText> 
                    <apex:outputText value="{0,date,dd/MM/yyyy}" rendered="{!OR(NOT(p.material_group__c = 'N2'), NOT(p.material_group__c = 'A'))}"> 
                        <apex:param value="{!p.planned_ship_date__c}"/> 
                    </apex:outputText>
                 </apex:column>  

ERROR 1: Show visualforce codes on column instead of value that is within " " double quotes,
without throwing any error

ATTEMPT 2

                 <apex:column title="Estimated Delivery Date at time of Order">
                     <apex:facet name="header">EDD</apex:facet>              
                      <apex:outputText value="{!IF(OR(p.material_group__c = 'N2',p.material_group__c = 'L2'),'week of-{0, date, MM'/'d'/'yyyy}','{0, date, MM'/'d'/'yyyy}')}">
                        <apex:param value="{!p.planned_ship_date__c}" />                            
                    </apex:outputText>  

ERROR 2: Incorrect parameter type for operator '/'. Expected Number,
received Text

But it seems, i can't have two apex:outputText on the same column. So how should I go about it?
Thanks