Recommendation of management/letting agency

I recommend this agency: http://www.home-consult.be/en/

It is a small, family business.

Run away from big companies....

And talk to your notaire/notaris. Renting out involves contracts and there are many pitfalls along that route, not least being the need to give proper notice to terminate even a fixed term lease (otherwise it just rolls over, probably into a nine-year lease).

More things to think of.
Have you got a mortgage? Is your mortgage lender happy with your plan?
Short periods. How short? And what will you do when you return if your tenant is still in the place and refuses to move out?
You definitely need to get legal advice and think very carefully as to whether it is a good idea after all. If you find yourselves having to live in an hotel, even if only for a couple of weeks, whilst you get someone thrown out is likely to mean that you end up losing money on the deal.