Heads up: The older version F1 editions originally inspired by uncle Kevy at UpscaleAudio back then sound quite different (veiled over, soupy) compared to a much newer SLP-98 from the past few years. A friend resold his older 98 F1 version and bought a current 98 version with some changes, with the better Mundorf caps. Heard them side-by-side paired up with different amps and his Harbeth 40.1 speakers. The newer 98 is different sounding, can be notably more transparent too. A designer who came on after Dennis left tweaked it a little more, as I understand it, and we spoke about it directly before I bought mine.
Along with the right caps, simply changing the 6SN7s in the later version 98 can give it five different sounds if you must try various 6SN7s. I run the newer version myself and each vintage or newer overseas 6SN7 changes the sound one way or the other depending on what you like. Sound can change notably with different interconnects on the newer 98 preamp, i've tried several, various designs with my 98. Its worth demoing and trying more than a few before buying ICs there too, as another recommendation for consideration.