This is my experience. Final Approach is Cadillac qulaity. Avery is not.
I have Avery Migrator, and being the size you 2 are, you definately need the bigger blind than a finisher. It can easily fold up to fit into the back of a short box PU. The basicac frame size is the same as the FA PG or TG. But it is not as sturdy or as well built as a FA IMO.
Now the 05 models of Final Approach Pro guide or Top Gun (both are same size, the top gun has a wp floor) can now collapse to fit into a short box PU too. The earlier models (04 and older) do not and are 7' L. The WP floor can be important when it is raining and a wet field (wet butt).
The FA Legacy is even bigger yet, but they quit making them this fall, a few dealers have them yet though.
There are other makers, but I have no experience with them, but few seem cheesier, Yugo type of quailty from the looks, so I'm a bit skeptical.
I'm selling my Migrator and will be buying another FA if that tells you anything.