I want a Link Point to point in distance 8 Kilometer for minimum 30 megabyte Speed.

What Radio and Antena i must Use?

RB912UAG class.... 2.4GHz or 5GHz boards and high gain dual pol parabolic antennas (at least 19 dBi for 2.4GHz and at least 25 dBi for 5GHz)
on 20MHz channel on a clean link you'll be fine.

30 megabyte or 30 Mbit/sec ?

30 megabyte or 30 Mbit/sec ?

I'm sure is 30mbps....

its easy sir just 32db with Rb912 its ok and more
look to this link

30 megabyte or 30 Mbit/sec ?

it's 30 MBps (MegaByte/ps)

My idea is for Camera Transmitters

Then you're talking 30 x 8 mbps throughput.
Different ballgame.
Back to my initial recommendation you might be able to achieve that with the same gear on 40 MHz channel... if you're lucky