Personally I'd ease Gonzales in, any old muppet can see Butt's best days are behind him now, but particularly away from home I think it would be foolish to assume the new boy is going to come in and be the playmaker we so desperately need.
I think Hull at home would be a prime time for him to show his credentials. He'll get plenty of time and space on the ball and they aren't the greatest presence physically. It's important if he isn't brilliant against Hull we don't write him off and similarly if he has a particularly good game we praise him as the man we've been looking for.
I'd continue in this fashion playing him against teams that will attack us at home but aren't anything to fear in terms of stature. Hopefully this will help him grow in confidence and eventually I'd consider playing him away from home. It's important to remember he's an unknown, just because he's an attacking midfielder, a position we've begged to be filled it doesn't mean he's going to come into our game and set it al alight. I think if he's decent I'd even consider taking him on loan for a second season before we think about a purchase.
In either scenario at home I'd go with the 4-3-1-2 with either Owen or Gonzales in the "hole". The new role for Owen reminds of how much I love KK as a manger. His timing and arrival in the box on cue has increased ten-fold since he was deplyed in the attacking midfield role. Alternatively if Gonzales is played his service can only help Owen in a centre forward role. The problem there is if the playmaker role is filled who do you play up top. Do you go big man little man with Viduka or Xisco knocking balls down and laying passes off to either Martins or Owen, or do you go with two little men streching the opposition back line (I have considered two big men for obvious reasons). It depends on the opposition for me. Those with a high back line or slower centre backs can be expolited by the latter, while against better back lines it may be better to mix it up a bit. That of course poses a very nice selection dilema to have.
Away from home as much as I'd love to go all guns blazing I'd like to take a sightly more cautious approach. Now I'm not saying we go ten men behind the ball Allerdyce style, but perhaps try something like 3-5-3. This dissolves the boundries somewhat between defence and counter attack. Under pressure the wing backs come back and provide cover and when going forward they provide supposrt. I'd seriously consider someone like Jonas in that kind of role. It may even benafit Beye in terms of confidence, being able to venture forward a bit more. Alternatively there's a 4-2-3-1 which is a bit narrow but you hve two men ala Butt and Guthrie protecting the back four and three midfielders in more attacking roles. I think this could work with Zoggy and Jonas in the more attacking wide roles.
Also I would't worry about Butt too much. I see Guthrie as a natural replacement. I think his distribution and ability to create a yard for himself on the ball means he should be able to do well in that role, maybe not at this moment in time but he will grow in stature as his career develops.