I have been working out for a solid 10 years. I have done a few different things. For what you want you really only need 1hr in the gym, maybe 1:20 min. Jumping rope is great for you and easier on the knees then running. I used to do a circuit of jumping rope and abs:
Jump with both feet 50x
On right foot 25x
On Left foot 25x
Running in place kicking your heels close to your butt 50x
"boxer" style where you kick your toes out in front 50x (takes a little practice)
Then get a workout ball:
Do sit-ups...right/middle/left, that's one rep. I would do 30 reps, eventually with a weight behind my head.
Do this 3x and your done your cardio and abs.
Then go do your weight lifting of 3 sets 12/10/8, increasing the weight each set. 3 excersises at least for each muscle group. If I was doing my chest or bis that day I wouldn't jump rope because I didn't want to fatigue them, I wanted them as strong as possible. Just start off by doing bis,tris,chest,shoulders (not all the same day).
All this is pretty basic but I was shredded to the max! I have seen the results of cross fit and P90x. I have to say they work great. I'm just not that dedicated.
I have mostly been 150-153ilbs and I'm just about 6foot. Struggled forever to gain size. Now, probably not what your looking for but I changed my diet and my routine. I gained 15lbs in about 6 weeks. Got stronger in every area, and went from a 170lb bench max to 225lbs 3x. That's impressive for my midsize frame. If anyone wants this workout PM me I'll shoot it over, it's a little crazy though.
Forgot to mention-after four weeks your random exploring needs to end or you will never see anything close to the results you want. Also, if you haven't jumped rope before just try and do 20-25x each jump set and 10-15 reps for the abs.
These are things that have worked for me. I feel they may work for you but I am not officially qualified to give advice so take it how ever you want.