I think two things about what you're writing:
- I think it is bonkers when people say 'oh, I love children!' in the same way they'd say 'oh, I love burgers!'. Children are people. I don't 'like adults', I like people I care about and find a connection with. I don't 'like children', I like children I care about and find a connection with.
It's harder to find a connection with children rather than adults because they're so, so different to us, but I am close to the children of very close friends, and my nieces.
I can't play with children though - not even my own! I'm rubbish at it! I'm very good at treating them like people though and I enjoy my own children's company hugely - they're lovely to have around, great to talk to, funny - I have four!
So don't base your decision on whether or not you like children. Your own children will not be just 'children', they will be people you have a very special, very close connection with, and, because you will live with them for a very long time, your connection and affection for eachother will grow and grow 
- Whether or not it will be good for your marriage: If you both want children, and you work well as a team, and both respect eachother and your respective roles (whatever you choose them to be) and you are kind to eachother, then your marriage is likely to get stronger.
I have strong views about marriage, and believe that if both parties feel strongly that they want their marriage to work, they will be able to overcome anything if they refuse to give in and work with eachother honestly, openly and kindly. If one partner doesn't, that's when marriages fail. So I guess it all depends on how you and your partner feel about marriage. If having children would break it, then so might a stressful house-move, or a family bereavement.
The other thing to bear in mind when you have children, is that you all should, IMO, try to take eachother seriously equally, which means that the children don't necessarily come first, but that doesn't mean they should ever suffer just so that you and your partner get time together. DH's and my marriage got much stronger when we both read a book about this - Winning Parent, Winning Child - and we worked out better ways of finding solutions that meant that the ocassions when a decision was made that made someone unhappy became far rarer. And DH and I didn't have to sacrifice our time together, and the children didn't have to suffer at all.
I think I'm saying that, if you start as you mean to go on and make it a principle to think creatively together to make sure that no one loses out - you, DH or your child/ren - then you stand a good chance of just strengthening your marriage, rather than weakening it 