istDS and Fujica screw lenses-do they work together???

Hello,

Recently I have been considering buying istDS, just wonder if it is
going to work with my dearest fujica screw mount lenses. Of course, I
know that adaptor is required. My comcern is that Fujica lenses are a
bit different than conventional m42/screw mount lenses-they enable
full aperture light metering.
So how will it be with pentax digital, which even doesn't have
aperture ring on its kit lense?
Anyone used fujica lenses with istDS?
And maybe with other dSLRs(Canon RebelXT=350D)???
Will full aperture light metering be a problem(that I will only be
able to shoot with fully opened aperture?
cheers,

Michal