Under £400 drone with follow-me and GoPro compatibility?

I'm going to buy the new GoPro Hero 5 with the Karma grip and gimbal for £600. I was going to buy the Karma drone as well for an extra £400 but I'm disappointed there's no follow-me or obstacle avoidance.

Are there any alternatives for around £400 or less with follow-me and obstacle avoidance that I could attach the GoPro to?

Portability is a slight necessity for me, but if that's not possible I won't mind too much not having it.

Thanks for any help!

Ps - I am a newbie, be nice