However I'd choose the Echo out of those two options. Echos are somewhat devalued and previously-owned by a better demographic than old Civics IMO. Civic values are inflated, so many Civics are riced, even the ones that aren't riced are likely to have been owned by a reckless kid, etc.
I love the look of the HX, but I have to admit that the Echo is a good buy. It actually drove pretty well and got decent mileage. I drove a friend's once, and I actually outran a Saturn SC1 in it (with 2 passengers in the Echo).
I think that both of them will be very reliable and net you driving enjoyment and good mileage. I would just base your decision on the actual vehicles you find (condition, price, # of miles, etc.).