Simple question re. readbacks

[XiRho]

Hi, just a simple question which should have a very straightforward answer. I have tried searching for it myself but want it clarified by the people in the know.

Is it appropriate to use 'Wilco' as a response to a request to make a position report?

ie.

"Cleared to enter controlled airspace not above 2000' VFR report overhead xxxx"
- "Cleared to enter controlled airspace not above 2000' VFR Wilco"

Or should it be read back "will report overhead xxxx"

Similarly, in what may be a more controlled situation.

"Cleared VOR DME approach r/w 35 report 5 DME"
-"Cleared VOR DME approach r/w 35 wilco"

or

"Climb FL210 report passing FL140"
-"Climbing FL210 wilco"

I' sure you get the drift!

Thanks very much for replies.