Spark Plugs gap and Performance

Hello and thanks for looking, and any help you can give is welcome. I have a few questions this time. Ok so about week ago the check engine(not vehicle) came on. I took it to Autozone for a computer read and was told that there was a misfire in C2. Well I decided to check the simple things first. I bought a bottle of injector cleaner and that seems to have fixed the problem now that it has run its course. Really the car even runs better.
But I did manage to take the plugs out after some research about what that manifold on top was for. Very Clever by the way GM. I don't really like clever from engine builders. I would prefer them to be off set to the side with the wire like in my thunderbird but guess thats just how I4 works. Anyway I did get to look at the plugs and to the best of my knowledge they aren't suposed to be that gray around the arc points. So I intend to replace them.

Here is what I need to know. What is the gap I need for the plugs?
Will changing the plugs mess with the timing in a I4?
If so what do I need to do to set the timing?
And I was wondering if any one knew anything about V-Plugs. I saw in the store why I was getting the cleaner that These Bosch Platium V plugs are suposed to be better than normal plugs and give better gas mileage, so was wondering if I should invest a few extra dollars to get them or if I should just stay with the single?

Thanks for any help and time.

when you get the plugs you want they will give you the gap but also it should be under hood what the gap is. i never did like bosch plugs that is. i would stay oe or get platnum one step up. but i tell you what my father took out bosch's out of his genarater witch it came out with. it wouldn't start so he put one of my ngks in it fired right up he is set on ngks. this was in the middle of winter also

good luck..

Ok thanks didn't know guess I will just stick to the normal plugs then. I didn't know if they would give me the gap or not so thanks for that too.