[Q] Root after unlocking bootloader, retain stock rom & bootloader topic

I am sorry if this is a dupe of other threads but I couldn't find a complete answer to my problem anywhere else.

I have a nexus 7 (2012), on stock 4.4.2, unlocked bootloader (i think, unlocked padlock on startup).

I want to root. I gather this will not wipe? (or will it?) and what tool should i use? I already have N7 toolkit and android sdk, so i can use that most easily, otherwise any other program needed is fine. I want to use stock bootloader and stock rom and ensure ota updates will occur. (i understand i may lose root through ota updates, but i assume i can just reroot as i have unlocked the bootloader?)

Thanks