Just figured that ordering GTA V through greenmangaming gives me the most value @ £30.90, moreso than getting it through work with my discount because; it would include $300K more for the online, which is worth around a fiver itself; it includes a Steam copy of San Andreas too.
Just a heads-up for anyone interested, I used a 23% off promo they're running at the moment which was delivered to my e-mail but when visiting the website it did promt me to collect a 23% off code anyway. So, the offer should be open to all.
So, does the actual GTA V code activate on steam?

- sorry </grammar_nazi>)