Before you change equipment I too strongly recommend playing with speaker placement AND listening position. I too had this exact same issue when I got my floorstanders (Spendor D7.2) and thought a sub could fix it, it didn’t sound ‘better’, I could just hear an exaggerated boomy bass that was separate to the speakers. So I spent hours moving the speakers around and at the same time moving my listening position around. What you might have is a null where you are sat which is cancelling out the bass. If you find standing in different places gives you more bass, then there is bass in your setup, you just need to find the listening position coupled with speaker placement that is the bass sweet spot. I have the Hegel H390 and personally love it, the bass it produces has a wonderful tone that is addictive. I am not suggesting it is THE amp or that it will improve things, just that I’m a happy owner of one of the amps you mentioned.
Room treatments will help the bass response further but just make sure if you are going to use them you get something that will actually make a difference. For the lower frequencies it is all about the depth of the trap, thin traps will do nothing to slow down the lower frequency waves which can be cancelling each other out.
Finally once I had found my preferred speaker and listening position, I purchased a basic app called HouseCurve and that was a super cheap way to get some feedback on the in room frequency response. This app is in no way professional like REW, however it did give me the frequency ranges that I had bass dip in which I then boosted with parametric EQ and reduced slightly the upper frequency peaks. Together that massively balanced out the sound bringing the bass through even more. If the highs are dominant you’ll notice them more and reducing them slightly can bring through more bass perception.
My big takeaway is there is a lot you can do, which really is the fun of owning a system, the tweaking and trialing things. Simply replacing the amp may not bring any improvements if it’s actually the room and placement of speakers and seat that are the issue. Try all of the above first and if there are no improvements then you may need to upgrade. I’m from the UK and we tend to try and not run subs, your floorstanders will have enough bass and it is better (imo) to get it out of them rather than just over-boosting the bass with subs that aren’t integrated properly. I now don’t use a sub for music as my setup has it all following the work I carried out above, the sub only gets turned on for films and at this point only provides rumble.