Well done. Good approach. As you've sorted the bike bit, I'll just chip in with my thoughts on trailers.
1. Received advice is that baby should not go in a trailer until it can support its own head.
2. Baby near always falls asleep and lolls very oddly within minutes of pulling away in trailer.
3. A good well fitted car seat avoids this problem.
4. Rigging a trailer to accept a car seat is fairly straight forward.
5. Get one that folds, and have a lock for it. Dragging trailer in and out of house / friends house / nurseries / coffee shops can be a pain.
6. It is almost always less pain than doing the same with a super trendy all terrain double buggy.
7. If relevant, get two hitches for the trailer, and have a spare seat in it.
We found the price and size differential between a single and double trailer to be negligible, and the extra space gives a lot more flexibility regards baggage, friends, picnic hampers, etc. A spare hitch means after loading it up with baby + play date, you and a friend can take turns to haul it.
We love ours.
Andy.