Intergrated amp for Totem Sttaf

Are they easy to maintenance?

yes, but occasionally you need to replace tubes. This doesn't happen very often. Depending on use, it might be every few years.

What is the minimum watt can drive my speakers?

I found that 50 tube watts was enough to drive my 87dB speakers to a reasonable volume. Your Staff are 88dB. Doubling the power to 100 watts will only increase the SPL by 3 dB, but the difference in cost between 50 and 100 tube watts is huge.

A watt is a watt, but tube watts go further than SS. When a tube amp is pushed beyond its limit, there isn't a harsh break up like you hear with SS. SS clipping can damage your speakers which is why it's a good idea to have more than enough power when using them. Musical peaks can push a SS amp to clip. A tube amp breaks up much more gently and forgiving.

What about upgrading your source? I don't know what cd player you use but the amp is only good as the signal it's fed, a good source makes all the difference on gear that can show it. The recommendations already offered will be worthy but more than likely, just different than what you have. To get a whole lot better sound in an integrated you may need to spend quite a bit more as the Arcam 300 in direct mode, bi-amped holds it's own with any sub 2K unit I have heard. You can get different, but one persons different may not be better. The AVR350 may be the ticket as it is similar in sonic signature to the 300 but more open and detailed with much better low end from a better power supply, caps and pre-section. I've had both and the upgrade is substantial, I was quite surprised. Another logical upgrade may be the Arcam FMJ32 but I haven't heard it. I've had the Bryston B100SST, Naim Nait 5i, Exposure 2010, Sim I5, Unico, Plinius 8150i. They are all great amps but I wouldn't put any in a higher class than the 350 bi-amped. In fact, to me the Arcam has the best balance of all and it's versatile.

Lamcam,

I would strongly advise against the Jolida/Sttaf combo. It's flat out a nasty.

High quality tube amplifiers are relatively simple to maintain. The easiest way to dip into the tube world is to start by finding an amp that uses auto-bias, is outfitted with current production tubes that are easy to find and affordable. (whispers, the Vista Audio products fit all of the above). As Mingles said; you'll have to replace the power tubes every so often. Otherwise, theres not much effort that needs to go into enjoying the tube sound.

"What about upgrading your source?" - I am using Naim CD5i and like it a lot. It's better to my ears than the Rega Apollo.
Can tube amp sit inside the cabinet? I need to hide it from my little boy.

I'd think seriously about a Tube integrated - and while 50-60 w/c would be nice, 30 will do just fine. I had played Sttafs for a short while on a vintage Fisher tube integrated. It was rated at ~20w/ch and it drove the Sttafs very nicely. Unless you want to rock out (which Sttafs don't do in the first place) you can do very nicely with 20-30 w/ch. If you only need one input the TAD 60 would be amazing with the Sttafs. Otherwise there's an abundance of tube integrated in the <$1000 price range (used), and some ~$500 range that would be worth a try IMHO. I no longer have the Sttafs, but I've driven my Mani-2s with my TAD 60 running in triode mode (30 w/c) and it was quite nice. The Manis are much harder to drive than the Staffs.