While I wouldn't want to discourage you from picking up a nice mechanical OM body, regarding IR and EOS, I believe a EOS 1V does not use IR for sprocket detection, but something like an Elan 7E does.
And to throw some more controversy out there, since you're looking for a new body...
for IR, I think a range finder or any sort would be preferable over an SLR, just because the IR filters are almost opaque to the human eye. Also, I think the quality of your fine zuiko's might be lost in the IR rendering.
But there's more to taking the photos, than just technical nit picks that I've mentioned.