I have a small rig and a larger rig. The small one is a 110w Phil Jones Bass combo which I use when I play at my synagogue's "Jam Band Shabbat" along with a host of mostly acoustic instruments. The main rig is a Trickfish Bullhead 1K which I dearly love. Large knobs and lighted push buttons - just can't beat it on a dark stage. It has zero noise. I run the Trick into a pair of Phil Jones Bass C4 cabinets. Previously I had a Schroeder 1210PL but the combo was just a bit too high fi, a bit too sterile for me. The C4s are perfect and the combination produces the sound I hear in my head. Strings are more of a challenge. When my only bass was a '78 Stingray, I just used Roto Swing Bass strings, but I was playing mostly hard rock.I have the above mentioned pair of bongo 6's and put my usual D'Adarrio EXL-170-6 on the first used one. When the new Bongo 6 arrived it had the Slinky's on it and I could A/B them. They both sounded great but the D'Adarrio's sound a bit warmer to me and they feel much smoother to the touch so I put D'Adarrio's on the 2nd Bongo 6 and am very happy with they way they sound and feel.
Strings are a very personal thing as is the amplification you use. My better amplification is a Mesa D-800+ or a WD-800 into one or two Subway 115's. My lighter rig is a Fender Rumble 800/210.
We are living in a terrific time when so much wonderful bass gear is available.
Now I play all kinds of tunes and have mellowed out, somewhat, in my old age, so a less aggressive string suits me better. But, overall, it's still rounds. The only flats that I've ever tried that I liked was a set of EB Cobalt flats, but they were on a bass I sold not long after putting them on, so I really have no long term experience with them. These days, it's LaBella and SIT for the most part.
Once the Slinkies die, I am not sure what I will try next, but if I had to guess it's probably going to be another set of LaBella Super Steps. Clarity and sustain that I have never encountered from any other string. I know a LOT of people love D'Addario, but I'm not one of them. Different strokes....