The official flyers and surviving tape/tracklist posts show a big multi-arena bill mixing hardcore, techno, breakbeat and rave names. Key billed DJs / acts included:

Lenny Dee (hardcore/hardtechno) — recorded sets from the night circulate.
Richie Hawtin
Laurent Garnier
Carl Cox
Robert Leiner
Paul Elstak
Loftgroover
Darkraver
Bass Generator
GTO DJ Squad (Greater Than One / GTO)
Slipmatt, Mach One, The Producer, Tom Wilson, Paul Elstak, plus a host of local crews and MCs.

(That lineup is visible on the original event flyer and in multiple bootleg/live-tape listings and forum posts.) (RollDaBeats Forum)

Who else / crews involved

Rezerection booked major international names alongside local Scottish & northern-UK talent — local crews, MCs and labels appeared on the bill (examples seen on the flyer: Ruffneck Records / The Ruffneck Alliance, PAS, and various Scottish acts such as Bass-X / The Rhythmic State). (dvcrewscotland.net)

Scale & atmosphere / memorable moments

Attendance & scale: Rez’s own history page describes Event 2 as an outdoor show that was “bigger and better organised” than Event 1, with an estimated crowd in the tens of thousands (many sources cite ~16,000 attendees for that summer event). The Royal Highland site was used for a number of very large Rez outdoor raves in the 1990s. (rezerection.net)
Distinctive cross-genre bill: What made Event 2 memorable was how it mixed hardcore/hardtechno heads (Lenny Dee, Paul Elstak, Slipmatt, etc.) with leading techno artists (Laurent Garnier, Richie Hawtin, Carl Cox). Attendees still comment that it felt international and eclectic for a Scottish outdoor rave of the era. (SoundCloud)
Bootleg recordings & tapes: Several recorded sets from that night circulate — Lenny Dee, Laurent Garnier, Bass Generator, The Producer and others have long bootleg/live sets from 30 July 1994 available on SoundCloud / Mixcloud / YouTube / Discogs releases. That’s why the night gets referenced a lot in DJ discographies and fan forums today. (SoundCloud)

Sources of eyewitness material (where this info comes from)

Rezerection’s own history page (short chronology and note about The Event 2). (rezerection.net)
Original flyers and scanned artwork (flyer lists most of the billed DJs).
Forum and fan posts that list the recorded/live sets and tapepacks (RollDaBeats forum, Discogs release entries, Mixcloud/SoundCloud uploads of sets). (RollDaBeats Forum)
Local rave archive pages / DVCrew Rez archives with additional scene background. (dvcrewscotland.net)

Anecdotes / what people still say about it

People who were there often remember the contrast between the harder, industrial-leaning stages (Lenny Dee, hard techno) and the more melodic/techno tents (Laurent Garnier/Richie Hawtin/Carl Cox) — that variety made it feel like multiple festivals in one. (SoundCloud)
The night is often referenced among collectors because tapepacks (multi-tape live recordings) were made and circulated later — Lenny Dee and others’ sets from the night are traded online. That’s why you can still hear the event today. (Discogs)