If you want the IR effect go with a Hoya 720 nm filter (IIRC. this was the cheapest filter available. I think I went through ebay) and then you'll want to rate it really low. Basically the film is way more sensitive to red light than it is to infrared light so if you can see well through the filter you'll still be getting the deep red effect. I think I used ASA 1.5 with that filter with good results in TMAX developer. It's been a year or three though.