You rised good points, this is my first (actually second) manufactured PCB so i still not have a defined idea to show you... 
What typeface can you advice to me? What's differences between top and bottom about logo design?
It's your logo... no offence intended as it seems you're starting out from scratch.
There is a significant difference between just placing type on a layer, and designing a 'logo'... check the dictionary.
A logo may contain typefaces - or not. Stylising your identity into a logo may present opportunities to use the specific medium (PCB artwork) to make it 'pop'... so you have an advantage there. e.g. using the dot of the letter 'i' to be the power on LED or something cheesy like that.
Recesses (voids in the PCB) may play a part - it's all up to your initial design - then carry it across to the front-panel, PCB, letterhead etc as you need.
It's great to think about this up front, as carrying some design elements across to other media may not work so easily... e.g. LED on letterhead.