A 5-6 watts SET integrated amplifier can give you enough power unless your listening are is extremely large and your speakers are too non-sensitive. Then there is no real need in hybrid setting.
I have a SS preamp which gives very comparable soundstage to a tube one. I mean not necessarily a tube preamp will give you better results. I am inclined to think that power amplifier is more important. A preamplifier can give you an additional flavour and it's up to you if you like it or not. If you have an integrated amplifier then you "get rid" of such kind of care, at least you don't need to search for a best preamp for your setting trusting to the amplifier designer.

