IP pump selection. Bosch VE or Cummins 4BT?

[subsonic]

I am in the process of pump selection for my build project.  I had planned on going the TD pump /Giles rebuild route.  Lately I have been thinking about the Cummins 4BT.  I will really only have enough money at this time to get one pump done up hard core.  This will be going on a 1.6 /1.9 head set-up.  This is going into a clean 85 golf NA I have.  Down the road I was planning on getting a Passat wagon.  I had planned to either go straight 1.9td at that time of go m-TDI.  If I go stright 1.9 I will be able to swap over many of my high dollar parts.  If I go m-tdi I am not sure what will swap, but if I have a Cummins, I know it will.  In the aspect of economy.  Can we use the Cummins 4BT on our IDI?  I see it ofton mentioned for the m-TDI setup.  I have read a few of the posts about fittment problems, but the seem solveable.  It's larger and stronger and will flow more fuel at higher pressure.  Pro's or Con's?  Will this support higher RPM range?  Anyone running one on a IDI setup?

Thanks, Jim