-what lenses will you be using for your 35mm
-It depends what time of day you will be out and about. Afternoons or midday.
- It depends on whether you will be in the city or suburbs.
- Before or after the time change... here's a quick google search to answer daylight and sunset times for Dallas.
http://www.timeanddate.com/sun/usa/dallas
To make it easy on you, i would use hp5+ 120 or equivalent for afternoons. I would push this to 1600's or at least 800. on medium format, the grain will be negligible but also give it a nice "film look" if there is lots of grain, while still maintaining detail in shadows.
during the day i would use the 35mm as I'm sure you will be moving around more. What film? that depends on what lenses you'll be using, Indoors/outdoors. 400 is a very adaptable film. just close the shutter a little more, but again, do you want some nice bokeh? I understand you mentioned 5.6 to 11 but was unsure of if that was for 35mm as well.
I personally like iso 25 on 35mm in the morning to midday, that way i can open up apertures all the way to 1.4 or 1.8 etc.
+I only shoot b/w, maybe you want color, IDK, but given the conditions, the very minimum seems to be iso 400. hp5 is easy to push, especially in medium format.