Like... do you trust this information you've been given, have you looked at your car yourself? Sounds suspect to me.
To add my 2p, I wouldn't pay the £700 for a standard system. I'd either source a good condition s/h system, have it repaired, or spend the extra and get a full BCS Powervalve system or Milltek system. Maybe even something budget that wasn't hooligan loud.
I find it surprising that the shocks have gone. What was the car used for, a porn set or farm car?
If the tyres are road legal get yourself Michelin Pilot Sport 4's from BlackCircles.com and get them fitted by a local garage.