No such thing as a " best" strain for hydro- Hydro's a technique, which will be appropriate for some situations, and not others.

Generally, though, hydro is associated ( in terms of this plant) with intensive indoor cultivation- you wanna look for a strain that will work well with the style of grow you're setting up. This is often a relatively compact indi/sat with limited stretch and a shorter flowering time.

If you've grown before, you might want to start w/ a variety that you're familiar with, as this will make it easier to troubleshoot any problems which might arise.

If you can say more about the style/design of the op, it'll be easier for folks to give meaningful input.