I don't know where you are diving - not that it makes a huge difference - but you don't need to worry about your integrated weights. Don't take the actually weights (doh!) but do take the BCD and the BCD pouches that hold the weight. You then get loose weights from the dive centre, put them in the BCD pouches and, presto, you have an integrated BCD.
Yep, just pack soft things around your 1st stage, transmitter and second stage - and obviously anything that is breakable, e.g. mask glass.
It's just common sense really and no different to packing for any other trip.
I reckon my dive bag usually weighs about 22kgs with all my dive gear, precious little extra clothing and my wash kit. Who needs anything else right? That's what credit cards are for.....
Enjoy the trip!