Nowdays you can grab a mobo off Newegg with SecureBoot support. The last three or four boards I've bought (Asus and Gigabyte 1155 boards) have all had SecureBoot support. To actually use SecureBoot:
1. it will have to be a UEFI board that has SecureBoot support
2. it will have to be configured to boot in UEFI-only mode (no legacy)
3. you will have to enable SecureBoot in the BIOS
4. you will have to load up the default SecureBoot keys in the BIOS
and now you can install Win8 and get functioning SecureBoot. To verify it worked, run PowerShell using a Run As Administrator, run the command Confirm-SecureBootUEFI and you should see this:
If you want to dual-boot with other OSes, that's where you can expect the rose to show its thorns. If their signatures aren't in the SecureBoot database, the mobo won't boot them. So you would have to switch off SecureBoot in your BIOS to boot them.