Hi Thorn, I'm sorry it's taken me so long to reply, I didn't have a chunk of time free until now. I've got a dodgy keyboard, btw, so watch out for missing 'p's!
The pattern of classes vs clinical time varies enormously according to where you study. I was at Kings College London and we had set hours of lectures for a couple of days a week, and the other days were for placements. But another uni I applied to did it in chunks instead - they'd have 5 or 6 weeks of academic stuff, then a 5 or 6 week block of clinical practice. Both have their advantages I think. My experience is out of date now, because I was the final year of the diploma option - we all started off on the diploma course, which got a small maintenance grant and then we had the option of 'fast tracking' to the degree course, most of which we could do still on the grant. UCAS squashed that though, and forced the unis to make it degree only, so that you don't get a grant and have to borrow loans to fund yourself. 
I don't know what the current childcare funding situation is, for that reason.
Basically the way they structure lectures vs clinical, how many nights you have to do in each year, how many on calls, how many long shifts etc varies hugely from uni to uni - your best bet would probably be to get on the forums and try to get current info from student MWs at the unis you're interested in. Sorry I can't be more help! We didn't have to do nights or longs at all in the 1st year, although some people chose to do so. I was incredibly lucky with my community placement and got a fantastic caseloading team - they do loads of on-call though, which is really tricky to arrange childcare for. How would you arrange childcare cover for a night on call (for which you only clock up hours IF you get called) and which might involve you a) not getting called at all b) getting called just at the end of your on-call period and then you want to stay there and catch the baby but it's almost 6.30am and you know you have to be home for 7am so your DH can go to work etc etc. It is tough, there's no denying it.
BUT, if when you catch that baby your whole world lights up and all the sleeplessness and juggling and your kids not seeing enough of you and your DH picking up the slack and the toll night shifts take on your body and the awful litigious nature of our modern NHS and the chronic underfunding and understaffing of our maternity service etc etc etc don't matter any more and you just feel joyous at helping a woman at the most vulnerable point in her life, and bringing new life into the world... well then maybe it will all be worth it. 
Oh, and there are part-time positions out there, certainly, but there are an awful lot of midwives after them!
I don't mean to be negative, just realistic. I've just spent the weekend with a woman from my course who is now a MW with a few years experience, and she hates the shifts but LOVES the job. I know quite a lot of MWs, and they all muddle through and enjoy what they do. Honestly, yes I'd leave it a couple of years and be there for your babies. On the other hand, on my course there was one woman who'd been a MSW and was seconded to train as a MW - she had a baby a month before starting the course (but had an incredibly supportive mum and DH to do childcare), and a woman with 5 sons 
ranging in age from 18 months to 18 years who had another baby just after she qualified (with an incredibly supportive DH but no other family support). Both of them went on to become successful and dedicated MWs.
It is possible, but you have to really really want it, and be prepared to sacrifice an awful lot to get it.
Best of luck whatever you decide. xx