I've just had a quick look at your website K, and will be going back - some fabulous work there!
I've tried all sorts of threads, but Superior are my favourite. Thanks for suggesting the combination, as I've been very unsure what might be best. I'll try that size of needle too - I think I have a different one at the moment.
You may see my post appear in the Janome forum!
Thankyou for all your help - I'll report back!