Sun stopped Solaris Intel download last Month. You have to pay 45USD to buy a media kit. Why not use Oracle 8i for Linux if you just want to learn oracle? use Redhat 6 + Oracle 8i for Linux. It's easy to get Redhat 6 and you can download Oracle for linux from otn or buy a book " oralce for linux starter kit" including oracle 8i CD.
If you really sick with Oracle on Solaris, why not buy a SPARC. You can buy a used Ultra10 around 1000CDN. Then you can get Solaris/Oracle SPARC version for free. You can try Solaris 9 beta, Oracle 9i 32/64bit.
BTW, if you really want Solaris 8 Intel and oracle 8i Intel. I have both of them. But it will be painful to install oracle/solaris on Intel platform. You will have problem with NIC/VGA etc. and don't forget to enable UDMA or HD performance very poor