I really like the score for Manhunter as well. Unfortunately the soundtrack has never been released on legit CD (only on LP and cassette way back in 1986), though bootleg CDs are being hawked on eBay constantly.
It's worth hunting the LP down if you're so inclined but I certainly wouldn't pay more than $30.00 (if that).
Jan Hammer said on Facebook that he wrote the track Red Dragon for this film but a scheduling conflict made it impossible for him to score it in the end. The track ended up on Snapshots.