Atmos Set up

[hd_newbie]

I am on the upgrade mood. I am looking to buy affordable speakers for movies and these seem difficult to beat.

Few questions:

1. I noticed using these as center channel was discussed. Did anybody compare? I have space to put the speaker in center and I may even be able to put it vertically. Should I? Or get their dedicated center?
2. I am planning to put together a 5.1.4 atmos set up with dedicated height channels (no in ceiling yet) this time around. Are these speakers wall mountable? i am wondering if I can mount them on ceiling itself.
3. What is best in my shoes for my 5.1.4 set up?
a) Get 9 HB1-MK2 for all speaker positions
b) Get 5 HB1-MK2 and use my existing KEF eggs (KEF 3005SE) for height duties
c) Get 8 HB1-MK2 and a dedicated center
d) Get 4 HB1-MK2, a dedicated center, and use my existing KEF eggs (KEF 3005SE) for height duties

Any input is appreciated.