For what it's worth thought... jumping small doubles when speed and air are reasonably low miscues most likely won't be the end of your season. I might suggest you make sure your judgement, decision making and skills are in line before going for the 50 footer. Can't believe I'm typing this but learn how to case and pancake (over jump) properly... yep, actually practice casing. Learn how to bring the front up/down, and straighten the sideways bike. Understanding these skills will help your jumping confidence as you'll know what to do in those mili-seconds prior coming up short or sideways.
It's all in the suspension setup... and the setup changes with each track and conditions, another must learn.
For what it's worth, get technique jumps will happen, not only that they'll be fun. You can search for books and vid's on the subject... personally, it would most likely be to your advantage to hang out at the track and ask the better riders to help you out. Mx guy's are brothers and most will go out of their way to get you in the right direction. I'd invite you to come over and ride with my son and I but the gas for you to get here could buy a lot of "how to" stuff.