I think for the low cost the best options have been mentioned in order: Zulu, DIYRe Colour...DIY Mojo Maestro...I wouldnt look to a compressor for saturation, and with Pre Amps well I compared the Colour format (Discrete Saturation) to a Warm Audio Tone Beast and they were pretty similar...even though a pre amp circuit is more complex it doesn't necessarily drive better IME...