Yes, you'll definitely want to opt for yohimbine, rauwolscine, or another controlled derivative versus full-spectrum yohimbe alkaloids; there's a lot of unstudied stuff in the full plant that seems to do more to make you feel like crap (nervous and jittery) than help with fat loss.
Yohimbine is extremely variable in individual tolerance levels. Especially combining with other strong stimulants like in an EC stack, you'll want to ramp up gradually to avoid an "I want to die" moment. I'd suggest starting at no more than 10mg (ideally more like 5) and ramping up gradually to your preferred tolerance level.
Also keep in mind that, unlike EC, Y's efficacy is highly dependent on your feeding state. Y really shines when you're well-fasted and doing some light to moderate activity, with its usefulness tapering off quite quickly if you've eaten recently.