FWIW I have had some experience with re-capping an ARC SP-15. There are "better" caps out there than ARC used, but the reason ARC used the caps they did was to achieve a particular voicing. Because the Ref 5SE is a spectacular preamp, and IMO sounds as good as anything they sell today I'd default to the ARC spec'd caps. Tube rolling is a safer way to get different voicing.
Additionally I'd replace all the similar caps at once. Caps are cheap and the balanced burn in will keep your precious 5SE in top form.