Yes, Helmholtz have been around for a while and do work. That is certainly a good option if you like the sound of your current set up. You can also replace stock front resonators with thicker ones for the drone but they will reduce the volume and change the tone.
I would recommend Eisenmann Sport + Catless. I can't get enough of that exhaust note! I take the long way home every chance I get and find tunnels to go through for a quick 4k rpm pull. Best part: NO DRONE even with the valves open.
E-sport will cost more than the custom jobs, but they make up for it in fit, finish, sound, and quality. Since you've already got the tips and muffler set up, Eisenmann may no longer be an option unless you can sell your set up. Either way, you have to get rid of the drone...I had muffler deletes and the drone got to me. With my current set up, I am 100% happy with my decision, it is a beautiful sound
evilb can attest to the quality of eisenmann!