I have managed to boot LE8 with 32efi by using the OE5 USB creator.
First, created a OE 5 Stick and installed it. Then just updated it to LE8.
Im absolutley new to Linux and this was the only solution for me to get LE8 to boot from ssd.
I also found out that my Board has a linux bios which i have to flash, but im not sure if i will get 64efi after that 
If there is another workaround please let me know.
My HTPC: Acer Aspire X1430 with AMD E-350 1,6ghz
4GB RAM, 64 GB SSD