[Nugit]

I would go with the eheim pump, that aquabee puts quite alot of heat into the water (though probably not an issue with a heatercore of that size).
With eheim you are sure to get a quiet and reliable pump, you might want to check out their compact series as well they are quite easy to mod to inline. Cheap as well, the 1046 equivalent will set you back 63kr. pp.

In regards to the waterblock, spirals look great with a plexi top but their performance isn't the really top notch. If your machinist it up for it, why not go for some kind of impingement block, to make a decent one isn't that hard. Just dig around the forum for inspiration.
Otherwise theres a #Rotor or a lumpy channel block, they're nothing fancy but yeild quite good performance.