It sounds like your concern is loading your child. Is anyone else riding in the back seat? I ask because I always preferred getting in the car with my kid on the other side from the child seat, then loading and buckling from next to it. So, if there is an open seating position without another child seat or booster, I would go that route and get whatever you like.
My BIL and SIL had an Element when their first was little. They had a pre-clicktight Britax convertible after a huge Britax infant seat with rebound bar. (This kid is 9 now, so it was a while ago.) And her parents are fairly tall. Basically, I think most seats would fit front-to-back. And with there only being two seats in the back, width shouldn't be a problem either.
If you'd like more specific recommendations, let us know how old, tall, and heavy your child is, as well as your budget. We'd be happy to help you narrow it down!