If I was doing it at Phillip my plan would be way more grandiose than that. What I'd do is move the play ground and skate park at Eddison park down around to the southern part of the park (behind the cemetery near the athletics field) then I'd drain the pond and build the new rectangular stadium over the top of that part of Eddison park. Then I'd knock down Phillip Oval and rebuild it into a proper 20-30k seater stadium for the AFL and cricket that would replace Manuka as the main oval venue in Canberra. Then I'd knock down the Phillip Swimming and Ice Skating Centre, build a new little rink with maybe 2-3k seats for the Brave and ice skating, but get rid of the pool and maybe, if it can be made to fit somewhere in there, replace the pool with a little 5-10k arena for basketball. Incentivize some of the car park companies that are already in Woden to expand their capacity where possible, maybe build a new multistory car park somewhere as well (maybe somewhere in-between the bus interchange and Hellenic club), build even more commercial space and hotels into the plans for the stadiums, and voila, you got yourself a great little sports precinct in a great spot that is easy to get to. I imagine that it'd be a pain in the arse to build over Sullivans Creek, you might even have serious trouble with environmentalists as though it doesn't look it at parts anymore, Sullivans Creek is actually a natural creek I believe. I'm also not sure how the ANU would feel about the plans, but Turner park wouldn't be a bad spot.