Fuji X-T1 does a reasonable job with an IR72, without modification. There's enough gain in the viewfinder to compose the photo, you can switch to B&W in the viewfinder whilst shooting RAW and the exposure meter is reasonably accurate too. https://flic.kr/p/JcRqww
Infrared shot of Foki Bay, Kefalonia, taken with an IR72 filter and processed in Silver Efex Pro 2. "Foki" is Greek for "Seals", there is a deep cave near the mouth of the bay where Mediteranean Monk Seals have been known to breed.
I've swapped from my Nikon-based system (though I still have it) to the Sony A6300. I needed something combining lightweight and high quality. The A6300 does this. These images are from my infrared converted (720nm) A6300. Advance Camera Services in Norfolk, UK did a first-class job with the conversion.This was my first outing with the camera. www.crhfoto.co.uk