If unsure about the right SCSI support, compile a kernel with all available SCSI drivers as modules. Load each module step by step until you get the right one.
AFAIK there is no laptop yet with a SCSI harddisk. Though there are two models with a built in SCSI port: Texas Instruments TI 4000 and HP OmniBook 800. Maybe the PowerBook G3 has a SCSI disk, but I didn't check this yet. The old Apple Powerbook Duo models had a SCSI hard disk.
For other models, if you need SCSI support you may get it by using a SCSI-PCMCIA card or via a SCSI adapter in a docking station.