You could use the excellent IPMI feature with full kvm support over the LAN... just sayin'
True enough, I just ignored its existence

due to the lack of habit using it - this is my first board with it. It works flawlessly, though!
Anyway the real issue was with the usb installation - I failed again and again with "no cd rom found" no matter what I did. The wiki
https://pve.proxmox.com/wiki/Install_from_USB_Stick simply doesn't work with 3.3 (tried dd, tried os forensic, re-downloaded the iso, changed the usb stcik and did everything again, tried putting the iso in _iso/mainmenu folder, got stuck on chroot part of
this post, SSD was recognized by the mobo, however, fdisk -l result was "no valid partition table" which I created with it, then it was ok), maybe it was working with version 2.* but not anymore. Suse ImageWritter on windows 8/8.1 x64 - no way, imho rufus is doing way better job than both of windows tools advised in the wiki. I couldn't find any useful tip/guide/advice how to make the usb installation work and this is supposed to be a relatively simple task, despite the fact that I am not using Linux every day. Out of patience I burned the iso on a dvd and just pulled dvd drive (which I didn't used in the past year, these devices are simply becoming obsolete) from my pc, connected it to the server and from this point installation went smoothly as expected and me following kobuki advice installed everything on the SSD which was there with valid partition written in my previous attempts. After the installation finished I left it running and went to bed - it is still running fine this morning. Please note that I do not reject the option that I did something wrong or not on the way it's supposed to, may be missed something or mobo doesn't like me or doesn't like proxmox - it was just a frustrating experience for me and lack of good guide didn't helped at all - if someone can provide me/help me with it I'll gladly reinstall everything to test it, I am still mad and want to make the usb installation running, it's almost 2015, it should work!!! and to be honest I want to know why it wasn't working on a first place.