Strategy for the next transfer window?

It's been sufficiently mentioned by Guus Hiddink and exposed by numerous EPL teams this season that we lack squad depth. Should we get more players? Should we trust youngsters like RLC,Traore? What should be our strategy going into next window? I'd say we should buy more players. I know I might get some grief for this,but I'd say as much as our Youth system integration should be smooth,we don't want to become a feeder club like Liverpool have become. So I'd say we should invest into some good world class players without loosing our own. Thoughts? I know this is a bit vague post,but which areas do you think need strengthening? Which players do you think can we buy realistically?