I want to replace my hammer on a stock Springfield 1911 GI. I want a "drop in' hammer that i can replace myself. right now I am looking at the Wilson combat : http://www.brownells.com/aspx/NS/store/ProductDetail.aspx?p=16419&title=1911+AUTO+VALUE+LINE+HAMMER+%26+SEAR is this good or do you guys have any better recomendations?

I would seriously talk to a gunsmith about this. There are alot of options and changing the hammer can change the sear engagement, making the gun not work proprerly...
Depending on the hammer selection you may have to change or modify the grip safety as well...
My 0.02

You cannot use that hammer with your current grip safety.  Why do you want to change the hammer?  I understand if you want to get rid of an MIM part, but I've never heard of a spur hammer made of MIM that broke.  Also, that particular Wilson is MIM also.  If it's for looks, don't bother.

Like it was said above, when you change a hammer, you run the risk of having different engagement angles.  That can mean a safety that no longer functions.  Hammers are simply not drop in, though they will drop in %99 of the time.  

You might consider saving up for a commander style hammer like that Wilson, and a beavertail, and the money to pay for a proper trigger job.  Just my two cents worth.

well I wanted to get the hamer first because I need to change the grip saftey and it will require a new hammer. the angle on the back of the stock grip saftey starts diging into my hand after 75-100 rounds. the new ones curve up and will fix his problem for me. So just wait and do both at the same time? I already ordered a triger will that drop in or is a gunsmith required for that as well?

Cylinder and slide ignition sets are available "prefitted".

Quoted: Cylinder and slide ignition sets are available "prefitted".

Perfect suggestion.  As far as the trigger, there are drop in and oversized.  Drop in almost always does drop in.  However, why would you want to replace the trigger?  The purposes of putting in a new trigger are:

- having less mass in the trigger itself, meaning less possibility of trigger bounce, but unless you tweak your sear srping, it should not be an issue.
-having less slop, as the vertical play is all but eliminated when an oversized trigger is fitted
-some triggers are adjustable for overtravel and takeup (pretravel).  
-many aftermarket triggers just plain look cool.

Anyway, fitting an oversized trigger is perhaps one of the easiest mods that can be done.  A drop in will most likely fit without any gunsmithing, though you do need to know how to detail strip the gun.  So, if you ordered a drop in one, you will not need a gunsmith per se, but you will need to know how to strip the frame.  Also, if it has an overtravel screw, do not adjust out too muchovertravel, as it could quickly ruin a trigger job (that is, if you get those aforementioned C&S parts).  If you have any more questions, let us all know.  In the meantime, welcome to the world of 1911 tinkering.  It gets addicting.