Wait! You are riding in Saudi?!

Maybe pack up SPD-SL's and go with clip-and-toe-strap setup. No need for cleat replacement or pedal wear; so you only need to care about bearings. I wouldn't bother with SPD-SL's. I mean plastic rubbing together with dust in it (and I am pretty sure you can't maintain too often), right? You'd probably destroy the flat pedals after your stay in Saudi, but flat pedal replacement would be more economical than having to replace wore-out pedals, cleats and perhaps cycling shoes. You can put em back on when you come back.

Oh don't do SpeedPlay. Dirt getting into the cleat interface would stop you dead from clipping in. Also, I think dust getting into cleat mechanism would be a bad thing. ... Everything else about SpeedPlay is supreme. Guess something to look forward to after you come back from Saudi.