if you do the dumbells, you probably better go for 12-8 reps than 5 * 5 sets which are perfect for big raw overall barbell exercises like deads, flat benches etc...
Here is a nice giant set routine, without the flat bench and doing the incline dumbell presses BEFORE the incline benchpress:
We use a rest-pause technique to allow a set of 8 hard reps to extend to 12 reps for each exercise. This is less hassle than drop sets using different weights.
Basically use a weight that allows 8 reps, drop or rack the weight, wait 15 seconds, crank out as much reps as possible (ussually 4-6 reps can be done)
Don't run like a madman between exercises doing giant sets, just get your next exercise going within 30-40 seconds...
Ok, here goes:
SESSION 1:
giant set 1:
- low incline (20-30 degrees) dumbell press 8(12) reps
- cable cross 8(12)
- low incine flyes 8(12)
- wide dips with bodyweight
- incline benchpress 8(12)
giant set 2:
- low incine flyes 8(12)
- cable cross 8(12)
- low incline (20-30 degrees) dumbell press 8(12) reps
- wide dips with bodyweight
- incline benchpress 8(12)
giant set 3:
- low incine flyes 8(12)
- cable cross 8(12)
- low incline (20-30 degrees) dumbell press 8(12) reps
- wide dips with bodyweight
- incline benchpress 8(12)
Done !
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SESSION 2:
giant set 1:
- low incine flyes 8(12)
- cable cross 8(12)
- low incline (20-30 degrees) dumbell press 8(12) reps
- wide dips with bodyweight
- incline benchpress 8(12)
giant set 2:
- low incline (20-30 degrees) dumbell press 8(12) reps
- cable cross 8(12)
- low incine flyes 8(12)
- wide dips with bodyweight
- incline benchpress 8(12)
giant set 3:
- low incline (20-30 degrees) dumbell press 8(12) reps
- cable cross 8(12)
- low incine flyes 8(12)
- wide dips with bodyweight
- incline benchpress 8(12)
DONE !