Having spent days reading up and watching youtube to find how to install Ubuntu Touch I'm happy to say the data settings where a dodle.
If anyone is interested the quickest way to install Ubuntu Touch is to buy a supported phone, then after rooting, backing up and unlocking the device you might consider installing Ubuntu dual boot and the rest is done for you from your phone.
If you're still not convinced consider one final thing, trying to install it on an unsupported device requires developer skills with or without which you and the phone still might brick it ;-)
1. choose Custom Internet APN
2. internet APN, giffgaff.com
3. Username, giffgaff
Password, leave blank
that's all I did and it went straight online and yes I did swich off wifi for the test.
I don't have any extra credit/ballance so I've not set up mms