Huh? You can upgrade an STE to 4MB by taking out the old 256K SIMMs and installing 1MB SIMMs! VERY EASY!!! No soldering or anything.
Same thing with a hard drive and CD-ROM. Just buy a SCSI host adapter, SCSI hard drive and SCSI CD-ROM, plug them all together and load the AHDI driver. EASY!!! No soldering or anything. Plug and play!
High density disk drives...well, ok, you're going to have to solder for that. :)