Hi H.,
Congrats!!! I am also awaiting baby number two and know that carriers will be the only way ;-)
I have three different kinds of carriers and find that they all have there different uses.
For short trips to the store I find using a sling works best - it was easy to quickly get my daughter in, wasn't bulky in the store and for less then an hours wear it didn't bother my shoulders or back. I would also wear it at the beach much lighter and cooer for both her and I.
For longer trips/adventures the ergo or mei tai were my favs. The support you get with both are great both for mom and baby. The only down fall i feel with these is that they are bulkier and not easy to just shove in the diaper bag when you don't want to use it or the baby just doesn't want to be in the carrier any longer.
I have also heard great reviews on the mouna wrap - which is made by a local south florida mom. I've heard the support is great and so far have not heard of one baby that hasn't liked it. Also very resonably priced.
www.mounawrap.com
Another local mom has an online biz and also does some of the local baby wearing meetings.
www.marsupialbabyslings.com
I agree with others that it may depend on your baby - i was lucky and my daughter loved them all.
I have not tried the bjorn becuase i had heard how horrible the support for the baby is. My understanding is that they sort of hang with the cloth between their legs.
I would deffinately check out a baby wearing meeting.
Good luck!
T.