Yes. Stick with the Heliopan 715 (which is equivalent to an 88A, I believe) I have also used a Wratten 87 successfully, but I like the results I get with the 88A better. You should be able to get good results with it. I shot this picture back in May with my 6x7 and an 88A filter.

http://dianemaher.fotopic.net/p5199700.html

And though this isn't a stellar example, I shot this with my 8x10 and an 88A filter just before Thanksgiving on a day where it was nearly sunset and there truly wasn't much light left (and it was overcast in the first place). It was simply one of those days that I had to get out of the house and take some pictures.

http://dianemaher.fotopic.net/p9564485.html