Hi
I have three "kumfy cotton" sleepsuits in size 0 (up to 6mo ish) I ordered from New Zealand no less!! They are great as they have integral mits and a high neckline to prevent scratching. I cut off the toes to get a bit more wear out of them, but if you dont mind that, then these could be what your little itchy one needs!
i also have one fully intact sleepsuit from "excema clothing.com" in size 70 (up to approx 9 mo)
After that i bought a pair of scratchsleeves which are doing the job in conjunction with two special babygroes (which you can have when she has outgrown them!)
All together they weigh approx 800g - so probably around £3 for postage, but i will check...
Pooter x