okay, to simplify this:
the thing that matters when fitting the bottom bracket in the frame is the width of the cartridge. both seem to be 68mm, which is fine. It must also have the same thread pattern. All are english by the sound of things, so that's okay.
Now, for the cranks to fit on the bottom bracket it must have the same spindle type. So, square taper cranks only fit on square taper axles. You can take a splined bottom bracket and cranks off and replace it all with square taper bb and cranks or vice versa. Just as long as they are both the same
now, as far as the bb axle length, you want to try to keep this the same as stock to keep the chainline straight. If you're stuck with this, the LBS is your friend.
so, short answer, yes. go for the cranks and bb if you want. it should fit.