I'd recommend starting with "Are you Shpongled" personally. More than Shpongle missing, I would have expected a sample from Hallucinogen (also Simon Posford's

I'd recommend starting with "Are you Shpongled" personally. More than Shpongle missing, I would have expected a sample from Hallucinogen (also Simon Posford's project) which predates Shpongle by a few years, and was at the forefront of the wave of Goa as it spilled over to the western world in its nascent years