I'd just concentrate on getting the tyres of my choice at the best price for the tyre and fitting.
The big on line tyre dealers such as Blackcircles and Mytyres offer a wide choice of tyres and a wide choice of approved tyre fitters in your area. Any of these fitters should be experienced in supplying and fitting sensors and responsible for ensuring they are working and properly programmed to your car.
I dont think the cost sensors is normally included in the quoted price , so it may be worth phoning a few potential fitters to see what they charge for these. Also check the small print as a few might charge extra for things like disposal of the old tyres or fitting to alloys.
But I would get them replaced. 9 years old is already pushing your luck. It would cost more to get the tyres dismounted, remounted and possibly rebalanced ,perhaps quite soon, as a separate task. Unless you expect to sell the car very soon - in which case is it cost effective buying new tyres?