Given the many problems you will encounter trying to fit anything other than a brand new OEM cluster to your X5, maybe a repair service like this is your best option.
BMW e38, E39, X5 and M5 Instrument cluster repair, lifetime warranty
I can't voucher for this particular repair service - but there are a few like this in the USA.
You might want to contact them first and discuss your particular issues - many cluster repair services only address missing pixels on the alpha-numeric (OBC/CC) display segment.
Let us know how you get on.
