Silverado 5.3 FI "T" tune up.

[Natch]

Drive an 02, Z-71 LT with the 5.3 FI "T" series motor. Have 53K original on her and all of a sudden I have a miss at idle and my mileage as dropped off some what.
Pulled a plug last night and it has the original Denso 16-15R double platinum OEM plugs and original wires. Fuel filter is new and I'm running a new K&N air filter.
Wanted to switch to either NGK or AC Delco Iridium plugs and Taylor wires, but couldn't find an application for the "T" series 5.3 on the Taylor web site.
Looking for recommendations on the best set up to get her running like she used to and get my mileage up to the paultry level that it was before.
Thanks