Ideas for kids playroom/den/study area???

[TryingToJuggle]

Hi I'm after ideas for the above really. Our house is a 1930's detached and we are planning on making the front room with bay window into the kids room. At the moment they are both little (DS and DD) so its full of toys but we want to 'future proof' it so we don't need to do it again ideally. The plan is to do a wall of storage on the wall with the chimney breast so all toys can be hidden away. Eventually there will be sofa and TV and on the opposite wall two desks for computers and homework.

It will be a blank canvas as we are stripping everything back and replastering so I need ideas for colours paint/wallpaper, curtains or blinds bearing in mind the bay window. What type of storage? I was thinking Ikea of some sort but haven't got any further than that really.

Thank you!

Friends of ours had cupboards built either side of the chimney breast, with shelving above, and deep drawers and wicker baskets. That meant there was somewhere to store all the toys but as the children grew older, the wicker baskets could hold all the game boy handsets etc and the shelves became book cases. It was all painted white and built in wood. Good quality, so it lasted. You could get a carpenter to quote. Other friends got a similar built in thing from IKEA which cost nearly 1000 and looked much cheaper, plus the drawers were far shallower and didn't fit things in so neatly.

Our family room has built in cupboards with shelves above either side of the fireplace.
The TV sits on the cupboard with kids DVDs & games in the cupboard. We have family books (atlas/maps/reference/games) & games on the shelves along with music books.
Toys / games in other cupboard.
The room is all White, with wooden floors (with rug) and a red ikea sofa. It's not too kiddy, but not too grown up either.
There is a side cabinet full of drawers for lego. The keyboard lives on a stand in here. Most toys are in bedroom but Lego lives in here.