It depends on how quickly we want to build and it depends on how much time Hughes has.
If he is seen as the man (and i've seen nothing to suggest otherwise) then i'd probably not do much until the summer. Give this squad time to gel. It's basically a new team and we're in 4th with a game in hand so it's not all doom and gloom. The Premier League is fast becoming the most competitve league in the world and there are a lot of sides who are very difficult to get results against. So in that respect, a win over Bunrley will see us taking 2 points per game which should be enough for the Champions League - which is very good.
Looking at it from a non-fan point of view (which is difficult) i'd still say we are a few players short of Chelsea and possibly the Scum (although they are open to debate).
I like Zabba and i like Micah, and if you combined their game you'd probably have one of the better right backs in the world. However, on their own they both have their own shortgivings that may possibly hold us back. Micah doesn't have a footballing brain and isn't a threat going forwards. Zabba is technically good, and he's ok defensively and ok going forward. He's solid in that respect but i don't think he's brilliant in any area (literally actually).
With that in mind, i'd go all out for Maicon. He had a little problem with his contract last season and it would have been the perfect time to steal in. He'd cost a fair bit and he's 28/29, but he is the best right back in the world (imo). He's brilliant going forward. That aspect of his game has the oppositions left winger, basically playing as a left back.
Moving on and again from a non-fan point of view, i still feel we are short of something in midfield. Somebody who can put their foot on the ball and dictate the tempo or control the game. Barry for me, hasn't done that yet. He's played well, but he hasn't really bossed any midfield battle. Ireland is the same. I love him to bits, and he's shown glimpses of doing this (schalke away), but he's not ready to do this week in week out yet. De Jong is great at what he does but he offers little going forwards.
With that in mind i'd look at Yaya Toure. He has the defensive dominance of De Jong along with the technical skills of Barry/Ireland. He also has the same physical dominance of a prime Vieira. He looks available, he's not playing for Barca (keita is in top form) and his brother plays here. I think it will happen.
I can't help thinking Jeremy Toulalan would be perfect for us aswell. Different sort of player to Toure obviously, but he's very good. He lies quite deep but he has brilliant technical skills. Almost like Pirlo but younger and quicker.
Of course form a fans point of view i have faith in what we've got and Johno is back soon (to full fitness) so it's maybe worth sticking with what we have, unless of course either of those 3 become available.