What are you using in it now?
You are working the little dear pretty hard, although the clutch will be the first part to suffer for this.
How much oil do you have to add now?
You do live in a warm climate, so I'd probably use a 10W-40.
If consumption is low, then Defy would be fine.
If leaks and consumption are more apparent, then I'd try Maxlife.
Some folks report good results in reducing leaks and consumption with PHM, so it might be worth a shot as well.
You are using this thing pretty hard, so I'd do maybe 4K drains, less often if you're adding a lot of oil between them.
This is not an application that would particularly benefit from Synpower or its blue cousin.