Primaluna prologue 2 based system upgrade

My modest first hifi system

Rega p3/24 ttpsu
Primaluna prologue 2 with built in phono and tube upgrade already.
Speakers MA RX6 + Basic Van Den Hul speaker cables.

Main concerns are the speakers, they dont disapear from the system, they are 6ohm and cant really find a sweet spot for these on the 4 or 8 ohm taps of the amp. Maybe something more tube friendly that will be a better match with the amp. I dont need lots of bass and the RX6 are a bit boomy to my taste, maybe its because the amp is just 40w...Better Imaging, something more suited for acoustic instruments and vocals just were the primaluna really shine!

Also will i get any benefit with power gear: wall outlets, power bar, power cord. Lots of people say its the first place to start while building a system but im a bit of an unbeliever and think its BS (no offense to anyone).

Also any advice on a decent sounding DAC, I just got back to vinyl and my record collection is a joke compared to whats on my hard drives...I think itll be handy to let the music flow through a playlist from time to time.

You might try some horn speakers, perhaps something from the Classic line of Klipsch, such as the Heresey's.
Sounds like your room or speaker placement might be your problem. Try to get the speakers and your listening position away from the back walls as far as possible. Try different widths and listen to the difference of the sound with the speakers firing straight ahead verses toed in to the listener. Make sure your speakers are in phase, + to +, - to-. How large is your room?
How about a speaker friendly amplifier. My friend tried a Primaluna. He didn't own it very long. Try a used amplifier from Audio Research, VTL, Manley or Conrad Johnson. You get what you pay for. If the new price is too high buy used.
Dill's post points in the right direction, IMHO. Electronics have a lot to do with sound but doing the 'disappearing act' is not so much matching speakers and electronics as proper placement of speakers AND your listening position. Good speakers (not necessarily great) are usually adequate for achieving a disappearing act if your set up issues are addressed. If these issues are not addressed you can spend all your want on new electronics and achieve nothing more than changing the tonal balance.

Now once you have achieved good fundamental stereo imaging using a good set up you might want to improve the tonal balance, imaging depth/width, etc, all of which will now possible.

Assuming that you have not really explored set up and want to, perhaps you could post a description of your room (its dimensions and furnishings, walls & windows) and how you presently have your system set up as well as restrictions which will impede any changes (like your wife :-). Quite a few folks here have extensive knowledge on this matter and should be able to help you. For example, you complain of 'boomy' speakers and think it might be connected to the amp you are using, and it could be, BUT it is more likely something as simple as where you have placed your listening chair (possibly in a bass node) or your speakers (due to boundry reinforcement)
IMHO RX6 is voiced for rock, you can't expect it to shine on acoustic music.