Hi,
It would depend of what do you want to achieve:
-Interaction Record should be used for "Interaction Center WebClient" Business Role as the main transaction type to register a contact/interaction with a customer for every channel (telephone/fax/email/face-to-face/chat, etc). Therefore the structure is simple: Description, note, a reason, a status and a priority.
-With a Service Request you are using a more structured transaction that will offer extra fields that are not available for a Interaction Record, such as:
-Two Multilevel Categorisation areas, usually for "Reason" (Subject) and for "Result" (Reason), that could be renamed to any requirement.
-Extra fields for processing such as Impact, Recommended Priority.
-Relationship with extra objects such as Related Problems, Related Request for Changes, Related Knowledge Article.
Additional a service transaction such as service request would offer:
-Find Related Problems.
-Find Related Knowledge Articles
-Autocomplete (to find automatically employee responsible/service team).
So basically you go option 1 or 2 depending of your requirement. If they are simple, you will have to configure less using an Activity (Interaction Record) rather than using a Service Request and then you would have to hide all fields that are not required.
Regards,
Lyda