Randolph and Sergio Rodriguez for Rashard Lewis? Lewis wants out, or so it seems, and the Blazers will have a bunch of money tied up with 3 big guys if they take Oden. Granted, the Sonics have a bunch of big guys, like Swift, Sene, Petro, and Wilcox, but Wilcox is the only starter. Petro looks to be the primary backup, and Sene is a developmental guy. Swift was injured all of last season, but was reported to be the starting center entering the season last year. Sonics are also pretty desperate for a good starting PG just a rough idea
You forgot probably their best big man -- Nick Collison. You didn't mention it but the article you likely got this from said Durant can't play the 4. I think the idea is silly. He's an outstanding rebounder, can block shots, and will only get stronger -- he can play the 4 in the new NBA.
If Lewis makes more than 11.4 or so million next year in a sign-and-trade, he becomes a BYC player, and the contract would count (in trades) for half of what he signs for. So it would take more than Lewis to match Zach's 13-million.
They should trade, but for the #1 (Oden) for #2 pick (Durant). I think both teams are better with that move. I'd say overall #1 (Oden) + bad contract (Raef or Miles) to Seattle for overall #2 (Durant) + Wilcox or possibly Collison (+ change) + Seattles 08 1st rounder going to Portland. I'd do it from both team's perspectives.