Barbel Mick, have you fitted led side lights already, you can gain almost 10w just from these.
Swapping the bulbs is a trick I used to do on the old Fireblade in the winter as it used to struggle with heated grips and clothing etc. Just changing one bulb was enough, but had to adjust the headlight aim down a bit to reduce glare to oncoming traffic, it also looked a bit odd so was more noticeable I think.
I also ran the Blade with a lithium battery for a while and this seemed to cope much better with the heated kit....the volt meter was always higher, not sure why but it worked. Maybe some on here would know why.
My heated jacket is by Biketek, no longer made, with a Gerbing controller and normally just use setting 1 of 5.
It's a good idea to always put the battery on charge the night before so its in tip top condition for the ride.
Would be interesting to hear what you end up with.