I have ordered one of these http://www.vishay.com/docs/81532/bpw96.pdf Photo Transistors with a 10K variable resistor. From what I can make out if I put the emitter to ground and use the 10K to pull the collector to 5v. I can then connect the collector to the input of my inverter. By adjusting the POT I should be able to adjust the light threshhold to cut out the effect of ambient light.
The Lamda for the BPW96B goes below 640nm and upto 1000nm so hopefully this device will work for my meter and conventional IR meters. The problem with the TSL261 I have is is low end cutoff is 800nm which is why its flaky with my red led meter.