If you are into tubes (and BTW, there are some very nice mods available for the SCA-35 at this link: http://www.tronola.com/html/a_new_look.html), the devices that are closest to tube operation are Static Induction Transistors (SITs).
They have linearity not unlike triodes and even have soft clipping like tubes.
The old Sony VFet used SITs, but Sony didn't have a good grasp on how to use them at the time and so the amps were a bit unstable. Nelson Pass has designed a new circuit employing the SITs. The problem of course is that SITs are no longer in production, you have to build the amp from a kit (if you can still get one, check with the DIY store on DIYaudio.com) and the amp only makes about 20 watts, but at least the latter is in the ballpark for you.
They have linearity not unlike triodes and even have soft clipping like tubes.
The old Sony VFet used SITs, but Sony didn't have a good grasp on how to use them at the time and so the amps were a bit unstable. Nelson Pass has designed a new circuit employing the SITs. The problem of course is that SITs are no longer in production, you have to build the amp from a kit (if you can still get one, check with the DIY store on DIYaudio.com) and the amp only makes about 20 watts, but at least the latter is in the ballpark for you.