More Power or use subwoofer to boost bass for music

Tweak the room by placing the speakers and dial in a sub so that it disappears. 

A small REL might be an intriguing option.  T/5i maybe. Their claim to fame is precise blending with existing speakers, using hi-level output and small fast subwoofers.

Hi very intresting tread and i want to add a little focus to another detail.

its ofcourse very importaint with the correct speaker placement but it is the same for the placement of the lisining position.
long ago Kevin Woecks from Shell/ Revel designed a smart software to calculate the first 3 standing waves in all 3 direktions x,y, z for the individual room size you plottet in.
The program even suggested some ideal ( best compromise ) placement for the speakers and the lisining position.
Beside that, you could print out the result and see how the standing waves increased or decreased when you changed positions of the speaker or lisining position.
Again in all direktions x,y and z.
This is a very nice tool to start your positioning. Depending on you speakers response in the bass you can make position corrections and actually have an idear what will happend.
Maybee some dealer still has the program installed and can help you.
If the standing waves are better controled it makes the bass feel more lifelike with better artikulation and punch beside that the midrange opends up.

I also expirenced that correct decoupling of all the equipment strongly affects the sound and in particular the bass very much but thats comon known but is actually also is very importaint what else you have in you lisining room. Every item that is in the room will somehow absorb music energy ( air preassure ) and even contribute to the sound with resonances, so you need to find a good ballance here too.

Also the placement of all the  equipment is critical and the worst place is right between the speakers where the SPL has the highest level. 

A cheap tweak is to get the equipment including all the cabels away from the floor so that there is no direct pfysical path for the vibrations between the speakers and equipment. 
Solid floor, walls and roof minimises the absorbtion of the depest bass but can be difficult to change but that might be a huge diffrence between the dealers room and yours.
I too think a pair of active subwoofer with frequency correction are a easy way the solve many of the problems in the bass range. And they have become so easy to operate via build in automation. 
 
Stay healthy and enjoy the music.

It you're thinking about a new pre amp you could demo the Anthem STR and play with ARC (Anthem's room correction). Also equipped with a very nice DAC. 

Good luck!

One interesting and inexpensive method to adjust your frequency response humps and dips in the room is to use the built in parametric EQ function in Roon - you can even use Roon for 14 days for free to try it out, play around with the EQ and if you can boost bass in the right frequency ranges and avoid "bloat" you may find that the $129 for a year is well worth it in addition to the user interface it provides...