just use hex dumbells, same thing as those t frames but you can actually use them for something else. explosive clap pushups are a good bench assistance excercise as well. ive recently started putting a 5 lb plate on either end of a barbell, elevating my feet, and doing pushups onto the barbell. you have to balance yourself or else the barbell rolls forward/back. you can also change the angle you are pressing, simulating a decline/incline press. add some bands over your back/weighted backpack and you can make a pretty interesting workout from pushup variations, though its no replacement for heavy presses. just something different to switch it up.