Car seat recommendation?

My son will be two 10/5. He needs a new car seat because I just can’t stand the one we have now and he just doesn’t fit comfortably in it like when we first bought it this time last year. He is a big boy. 36 inches tall, almost 40 lbs, he was 38 lbs last he was weighed. he is currently rear facing but I don’t think we will be able too much longer, he is just so cramped up. I don’t want something too large, I am expecting our second baby and I have a small car so we’ll have two seats in the back.