The closest to the 7 is a 7.
If you want most of the features of the 7 without the price, buy a 5. Should be under $20, still does wireless TTL flash, SSM, etc. Nowhere near the focus speed or ruggedness though, it's not a pro body.
If you want ruggedness but not modern features, get an older 8 or 9 series body.
Table of all Alpha/Dynax/Maxxum bodies.