will the specs of this 2nd hand hand built pc run cb9 well?

Gigabyte AMD FX6 core processor
8gb ram customisable to 64
120 ssd 500 hdd
Usb3
Windows 10
Mb: Gigabyte GA -78LMT-USB3

Processor:

https://www.scan.co.uk/products/amd-fx-6300-black-edition-vishera-six-core-am3plus-clock-35ghz-turbo-41ghz-8mb-l3-cache-95w-cpu-reta

. They want 160 quid for it. Im told by freinds AMD are bad processors for music and some softwares dont work with them? I need it to run my cubase pro 9 and be able to record 10 channels of audio at a time whilst monitoing live audio fx. I wont be using it to use loads of plugins etc just primarily a recording setup with an old tascam usb 2.0 16 input soundcard us1641 and at times my apollo twin usb 3.

Any advice or should i get intel?

To be 100% sure you should also ask the motherboard type and see if there are known issues with it. The the CPU should be 100% ok for you and some headroom too. I have a much older system (Intel though) and it is plenty for me and I use lots of plugins and vsti.
If you want second hand Intel, have a look at q9550 on a P5Q (asus). 8gb ram max though.

Gigabyte GA -78LMT-USB3

I did a quick google and I see no issues. 2 people here on the forum use it one with USB so seems ok.
The price is ok but not stellar.
But you will never know how it works until you try. Maybe a return option?
If the audio interface you want to use is old, windows 10 might be an issue but I see there are W8 drivers so probably ok.

It will be okay but won’t set any world records - for the outlay it will be a perfectly good PC. Some fx6300s overclock well (given decent cooling). I ran my old FX6300 at 4.2Ghz and it performed well at that speed. Of course you must disable all the speed step gubbins and run at a steady clock speed or Cubase will not behave. Depending on the version of windows you will also have to disable core parking. To be honest I think my FX6300 performed better than my current 8 core CPU for Cubase - perhaps I shouldn’t have been so hasty at giving it away!

That motherboard is limited to 95W CPUs only, but it’s generally pretty reliable.