Sending good vibes your way, Steph! It's so exciting to hear that heartbeat.
I don't know if I'll be much help on the stroller - we've only used ours a handful of times so far. We have an Inglesina Zippy, and I do like it - it's pretty easy to fold up one-handed and is easy to maneuver. But I've also heard great things about the BOB strollers and the Phil & Ted ones. We also have a friend's Maclaren umbrella stroller that looks really nice and light, though I haven't used it yet. I agree that it mostly depends what you want it for - what kind of terrain, does it have to go in and out of the car, do you have to haul it up stairs, etc.
I feel so fortunate with how great DH is with Willa. He's really as comfortable with her as I am, which is great. I think in part it's because his work schedule is pretty flexible, so he gets to spend a lot of time with her, but he's also just great with babies. He's always loved hanging out with our friends' babies, even when they were infants. He just got back from a 4-day trip, so Willa and I had lots of alone time together - I loved it, and she was great, but it also made me appreciate how much he helps when he's here. And there have probably been 5 or 6 evenings already where he's watched her and fed her pumped milk and put her down while I went out with some friends - which has been incredibly reinvigorating for me. I think if you can manage it at all, it's so good to have just even a couple hours of doing something for you, without a baby to care for. I know every mama is different, and some probably don't want even a few hours away, but for me I find it energizing.
Of course, we haven't been able to take an evening for the two of us yet, and I'm hoping we get to do that one of these days. But both our families live too far away to watch her (I guess we did actually have one date night back in August when my mom was visiting) and I haven't felt comfortable hiring a sitter to be with her. Right now I'm just trying to look at our evenings after Willa goes to bed (she's usually down by 7:30 or 7:45) as our time together. Not quite like going out for a real date, but it is some good adult time, which I find is important for keeping our own relationship healthy.
Oh - forgot to add that Willa is also on track to be a very chunky baby! We don't have a 4 month appointment (our doc doesn't do vax for any babies until at least 6 months old), but at her 3 month she was 16 lbs, and she's been growing steadily since then. Crazy! My dad actually asked, in all seriousness, this weekend, if I was worried about her weight. I had to keep myself from laughing. I explained that at this age, and with all breastfeeding, it was very healthy and I wasn't worried about her weight in the slightest. Then my mom dug out an old photo of my brother at 4 mo to show him - even fatter than Willa.