Help needed please :)

I know its a poor choice of song but one of my closest friends has asked me to accompany her in a duet at this big performance night. There will be around 500-600 people there and i really don't want to be making a fool of my self.

The song chosen was s club 7 - i really miss you ..which is infact sung entirely by rachael stevens on her own. I have used a few sites to find the tabs for this but when i play them it never seems to sound correct as though there are some chord changes missing and overall seems very vague.

I am also unsure about where to play the chords shown wether i should use standard basic chords or use barre chords to make the chords a higher pitch as when i play it sounds too low.

I would greatly appreciate it if someone could give me some help or advice on how to play this piece as i am struggling a great deal!..

If you need to hear the song search it on a video website and the music can be found on all well known tabbing websites..

If you would like to send any information that may breach the rules of this section of chordie forum please email justdannyd@hotmail.co.uk

Would be greatly appreciated thankyou.