I haven't used HDRi's much, but I would just use VRay sun, it's preconfigured so if you set it low from the horizon you automatically get that sunset glow. With regards to the vertical lines, it just makes all the vertical elements ...er.....vertical!. If you have a look at and decent architectural photography (Archdaily.com) you'll see that's what they try to do. Also You see that most of the great cg artists correct the perspective....