i don’t know those chinese willsenton amps but i think many of those new chinese brands sold direct are knock offs of primaluna designs... so they will perform pretty well, so long as they didn’t cheap out on the output transformers... i think you know with a tube amp you are hearing the output trannies as much as the power tubes driving - transformer quality is very very important
does the willsenton amp have a triode/ultra linear switch (like the primaluna’s do)? if so you will get a glimpse of what 300b’s will sound like -- more spatial cues, but less drive, a bit sweeter midrange, softer bass, more rolled off high treble if your amp can run in triode mode
your tektons are 4 ohm stated impedance even though they are quite high efficiency... that raises a red flag for me... can a 300b amp control the bass? they are less powerful for sure - so depends on your room and listening volume
other thing i would say is that chinese amps come with chinese el34’s (obviously)... they are the brightest (treble-centric) el34’s currently made imo (shuguangs)... so to alter the sound profile you might try a set of russian el34’s which will give you more body and less sizzle - the tektons are tuned to be very alive, so using the amp you have to ’round off’ the sound a bit through tube rolling the input and output tubes could well be more cost effective than going with a 300b amp...
my thoughts