How about a list of what conversions are on J2O?
(sorted by J2O rating, taken from the j2o downlopad list, tileset conversion type)

SCRAPARAP: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2245
DIAMONDUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2866
LAGUNICUS, ORBITUS, MEGAIRBASE: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2887
TURTEMPLE: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2916
NIPPIUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1736
HOLIDAIUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2161
DREEMPIPES: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2190
CERAMICUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2873
PEZROCK: http://www.jazz2online.com/J2Ov2/dow...php?levelID=94
MEDIVO: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1917
TUBELECTRIC: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2893
EXOTICUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=3190
BATTLESHIPS, CERAMICUS, JUNGROCK, LETNI, STONAR: http://www.jazz2online.com/J2Ov2/dow...p?levelID=3190
JUNGROCK: http://www.jazz2online.com/J2Ov2/dow...p?levelID=3258
PEZROCK: http://www.jazz2online.com/J2Ov2/dow...p?levelID=3346
MARBELARA: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1856
DESERTO: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1672
CANDION: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1797
LETNI: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=657
MUCKAMOK: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=973
TUBELECTRIC: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2137
SLUGGION: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1652
INDUSTRIUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2482
BATTLESHIPS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2223
STONAR: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2930
CRYSILIS: http://www.jazz2online.com/J2Ov2/dow...php?levelID=95
BLOXONIUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=3336
TUBELECTRIC: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=353
JUNGROCK: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=685
JUNGROCK: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1848
TECHNOIR: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=392
STONAR: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=641
EXOTICUS: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=679
SCRAPARAP: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1298
BLOXONIUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1685
RANEFORUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1693
STONAR: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1827
CERAMICUS: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=643
MEDIVO: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=646
INDUSTRIUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=2154
RANEFORUS: http://www.jazz2online.com/J2Ov2/dow...p?levelID=1905
BLOXONIUS: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=913
STONAR: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=644
NIPPIUS: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=876
CERAMICUS: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=640
CERAMICUS: http://www.jazz2online.com/J2Ov2/dow...hp?levelID=627

I might sort them in another way, but well, this list is somewhat complete I guess