<p>I'm looking for a strong filament that can handle a large tension load and no bending deformation when a perpendicular force is applied to it. Any suggestions?</p>

As far as I know, Nylon filaments are among the strongest. I'd look at the technical specs of
Taulman3D's Filament
. They're the only nylon I've ever tried, and I know they have in-depth specs of how their filament holds up. I'm sure you can find other providers, though.