My chest has always been a problem so I am more than happy to tell you what has been working for me. With the equiptment you have you can build a great chest. Id always start with incline before flat, and keep it heavy 6-8 reps. Then id do 3 sets of 8-12 with your dumbells, really focusing on the stretch and contraction. My problem was always finding the right hand placement/elbow flare. For me keeping my hands a little more than shoulder width apart and elbows tucked in, not flared out has done wonders on the bench. After the fly work do 3 sets of as many push ups you can till you hit failure. After youve hit failure, do 2 sets of 10 of ONLY the descending pushup. By the last rep you should almost plop to the floor. Now you have completely exhausted your chest muscles and they have no choice but to grow! Wow I just gave away my secret hahaha.