It sounds like you're having a fun time!
Chicken robot walker = Sectopod
If you want to get a Sniper with Snap Shot, you can hire rookies again and hope they level up as Snipers. The easy way to do this is to get the free Squaddie upgrade in the Officer Training School, then hire a rookie. Then, just one day before the rookie is "transferred" to your base, save your game. Wait and see if it turns out to be a Sniper. If not, reload and try again.
I know some people would think this is cheating, but since as far as I can make out the game totally randomises the class your soldier ends up becoming, this is the only economical way to try for a Sniper.
I don't have Ghost Armour yet, like you I am trying to research more tech before I trigger the alien base assault mission (because I want to get my Heavy Plasma before I go in ... .don't have enough weapon fragments for the research :0 ).
I think there is a new DLC coming out on 20th August, kinda looking forward to that.
Also looking forward to XCOM: The Bureau.