4 months uve dropped alot of inches from your belly dude, u just gotta keep it up, well done,u sound like a fit guy with alot of motivation.

IMO ab excersizes are good for training anytime & any1s weight,i wouldnt recommend them until you lose a few pounds on your belly, that way when you do work them youl actually see gains rather than the muscle being built being covered, plus you can utilise that energy and time in reaching your goal in losing exsessive size. core excersizes and others however such as pullups,dips etc should be a prioraty itl give you an amazing frame.

I was competing for a tournament in france couple of years ago..needed to shred some weight..used to shadow box,lunges,squats etc all in the sauna everyother day, it kinda fast forworded time for me.

i would simply recommend to just 'sweat it out' do natural excersizes use the cross trainer rather than a treadmill stick to running in the streets, remember to not do cardio for more than 45mins at one time though.