I have a question regarding your typical cheesy sunset photo, done with Velvia 50 ASA.

I am a novice in the medium format department, with only 3 rolls of 120 b&w film to show for (you can read my blog about my experience here, haha http://helino-photo.blogspot.com/201...um-format.html )

Previously I've used 35mm film in my Canon 1v and spot metered a few points in the scene to get a good exposure for my landscape shots.
This has worked out well.

However, I now want to try my luck with my newly purchased Hasselblad 503CW and I also have a Mamiya RZ67 pro II on the way in the mail.
The Mamiya will be my main landscape camera, and the 'Blad' will mostly be used for model photography.

I've thought about using the Hasselblad for a few landscape tests-shots (I only have the 80mm and a 160mm lens for that, nothing wide).

Now, the 'Blad' doesn't have a built-in light meter and the only meter I do have, is the Seconic L-358, which doesn't have spot metering.
This works fine for model photography, but how can I use this for landscape photography, especially when I have the sun in the frame, for example?
I plan to take shots like this, typically:

I could always use my 1ds mk II's spot meter to get a few readings, but what did/do people really use?

Oh, and I have a Cokin-P filter system with grad filters for my 1ds MK II and lenses, is it any way to get it to fit Hasselblad or Mamiya lenses properly?

Tips/pointers much apperciated. =)