The EF 50mm F/1.8 Mk II is a cheap plastic toy. It is a "disposable lens" if you will. That said, it has less barrel distortion than the 50mm F/1.4. I own F/1.4 and while I don't love it, I use it all the time. The original Mk I 50mm F/1.8 is very similar in build quality to the 35mm F/2. It brings entirely too much on the used market, so personally I'd just buy the 50mm F/1.4 USM when you're ready to spend $350 on a lens.
The 85mm F/1.8 is a great piece of glass. It has some CA (chromatic aberration - purple fringing) wide open, but other than that it is an excellent performer. You're going to be stopping it down a bit to gain back some depth of field, anyway. As long as you never use the 85mm F/1.2L USM Godzilla, you will always love the 85 F/1.8.