BMX and MTB are 22.2 diameter. Nitto bars are 23.8 mm beyond the central sleeve (which of course is 25.4 mm). DiaCompe makes two versions of the Goldfinger, one in 22.2 and the other in 25.4/26.0 with a reducer that takes it down to 22.2. So ... no joy. If you use either 25.4 or 26.0 bars with a slightly wider fat section in the middle (Nitto 018 bullhorns, for example), you can use a Goldfinger if you can find the right one. Unfortunately the 25.4 mm ones aren't normally imported into the US (which is more BMX oriented). If you want a couple of them, I got some last time I was overseas. Send me a PM.
If you need a lever for 23.8 mm, your choices are a cross lever (which is usually somewhat mediocre), an old Paul cross lever (which is pretty nice but no longer made) or a Paul E-lever (which is a relatively new product, still made, $52 per lever but does everything you want it to). The only downside to the E-lever is that you'll have to put up with all the kvetching about how expensive it is.