You want to go sealed. You can go ported if you like and get decent results, but for desktop, size would be a factor. That's really the main difference between that and bookshelf. Placement and environmental factors are the same. 30 degrees into the focal listening point and head level or angled to the head for best efficiency when dealing with sealed layouts.
The reason I would not recommend ported is due to near field response reflections of higher frequencies. By loading the enclosure with a port, you induce resonances more so than in room resonance, and when the two meet, they excite and become "hollow". This can be the effect of too small of a port and when dealing with proper response from "desktop" space, this is vital. No damping is required, no diffusers necessary, just plain accurate output. You are not looking to hit a 30hz note from a desktop enclosure with authority because that would be unnecessary due to placement and size issues. You would get some out of phase output either at the subrange or above it, so I'm sure you are not worried about that part. Have a dedicated sub for that, and make sealed enclosures based on the golden ratio and you should be fine.
You could make small passive radiators that are dipole for a more rich effect also.
And if sealed is not the route you want to go, due to the need for complexity and accomplishment, go full open baffle and place diffusers or acoustical absorbers behind them on the wall to reduce reflections.
As far as power, you should only need about 5 watts total. Then a separate 10 watt subamp. The sub, I would port....no question. Because in a room for home use, the gain drops much more than in vehicle so sealed subs are not recommended due to possible negative gain response at certain frequencies.