http://www.ciao.co.uk/Lidl_Disposable_Nappies__Review_5688013
and
http://www.mumsnet.com/Reviews/DisposableNappies/18-lidl-nappies/
they are the toujours ones
we were recommended them by someone in the street - Doc Jrs granny saw someone in lidl buying them and asked if they were any good - they said yes, so we gave them a go - out of our NCT group of six, 5 of the babies now use lidl nappies having tried them from us (so 5 out of 6 babies prefer them- ha ha!)
I reckon they are worth trying for the sake of a couple of quid - they certainty seem resilient to jrs dumps when he was younger - leaked alot less than the 'leading brands' (didn't stop the occasional exploding nappy though) - their baby wipes are pretty good too and we have used them since day 1 (or so) - jrs skin didnt like the johnson & johnson ones in the pink wrapper and also the pampers ones.
We currently change every 3-4 hours (when we remember - sometimes we are bad parents and completely forget) - but when he was small we I dont think we did any different - certainly didnt change every feed, and then maybe once during the night (current night regime is nappy at bedtime (6pm), then a change at 11pm (when we go to bed) and that lasts right through until he wakes us up at 6am)
oh, and you asked about pre-made formula - not sure about that, but we switched from SMA to Aptimil pretty much straight away (breast wasnt best - lots of mastitis and feeding poorly, so we switched to formula to supplement breast)- SMA cuased major constipation, followed by massive explosions of foul smelling green stuff (plus I am allergic to SMA - causes major asthma attacks!!). No such problems with Aptimil - but I guess each baby is different, so might not suit. Aptimil comes pre-made and I think is about 80p a carton (10oz?) or so - not sure about buying in bulk - or £8 for a tub of powder - Jr has thrived on it