Just get the 50 1.8, you'll not regret it, then also get something a little wider angle, perhaps a 28mm since you have a crop sensor (you'll find the 50 a little tight for some circumstances). Also since you are planning on doing mostly video and portraits (so AF isn't very important), you can pick up some old school manual lens for super cheap. I have an old vivitar 135mm f2.8 (circa 1970 I think) that I picked up for about $50 (including adapter). Image quality is very good with these old lenses, usually some chromatic abberation, but it's easy to correct for in post.