Allo chaps, ain't posted here in a while after a long stretch out of game but am now starting to get back into it again and have a minor query. Though I should warn I tend to ramble on a bit so bare with me here.
Basically I fancy a girl in work, I haven't worked there very long but we've been getting on like a house on fire and I think so far my game with her has been pretty solid, only reason I haven't "gone for the kill" yet is precisely because we work together, however I've just learned she is leaving the company soon

which should make everything that little bit easier.
Bit of recent history, after working together for a few weeks I suggested we go for a night out, some drinks etc and she invites me to come out with her and another guy that works there (he's gay with a boyfriend so no threat) I agree but tell her I'm going to house party first (being the busy sociable guy etc) and while I'm at the house party she keeps texting me asking where I am/how long I'm gonna be yada yada, by the time I meet up with her it's 1am and we're both pretty drunk so not much happens (I know, my bad), we exchange a few texts and work together once more about 3 weeks ago, since then I decided to do a freeze out just when things are going decent because I knew we weren't gonna work together or see each other for a while coz she was out of town, so to avoid becoming "that friendly guy from work I always speak to/text on the phone" I figured I'd freeze out and make absence/lack of attention make the heart grow fonder. Anyway found out this week she's leaving the company so sent her a text basically saying I heard about that and that we need to have a leaving party for her, she responded very positively with her seeming 'excited' to have got a text from me and says we'll arrange something on saturday in work.
So thanks for reading this far, here's what I'm a little stuck on. I'm not sure whether to go all out for a proper 'date' when I see her in work, so like invite her out just the 2 of us where she knows it's a date. Or alternatively arrange a leaving party/night out or whatever and make the move for k-close etc then.
I have 1 or 2 other girls 'on the go' at the moment as well anyway so not throwing all my eggs in one basket here but as I'm sure you all know, even when you have got a few options there is always 1 that sticks out as your first choice, this is the case here.
Any advice greatly appreciated guys, cheers.