If we don't sign a keeper, we've a good one and a decent one and can still function in the top half.
If we don't sign a centre half, we've three good ones and are still capable of finishing in the top half.
If we don't sign a central midfielder, and we're lucky with injuries and Barry doesn't have to play left back, we'll be okay.
If we don't sign a second powerful striker, we'll need to be lucky with injuries to Carew, or we'll struggle. (Although Luke is now a big lad.)
If we don't sign a back up left back, we'll need to be lucky with injuries, or we'll have to move Barry from midfield.
If we don't sign a right back, we'll have Mellberg and Gardner as our only options and we'll be ****.
So for me, that's one signing we absolutely need, a new right back just to stay where we are.
To improve, we need that right back and a back up right back, a back up left back, a left sided midfielder or a central midfielder, (depending on where we leave Barry), a centre half and a big striker.
Or, we'll need to be really really lucky.
I don't think you can leave all that until August. I'd be surprised if we don't have at least half of this in place by the time we cross the pond.