New business grade computer recommendations?

Hi All,

I have been recommending Lenovo's Think Station computer
to customers.   But I really do not like how proprietary
they are.  Repairing them is impossible after the warranty
period expires as Lenovo is the only source of parts
and Lenovo won't sell you parts after the warranty expires.

To name a few:

     Proprietary connectors on the motherboard to the SATA
     drives (power and data).  (Motherboard SATA pins that
     you have never seen before.)

     Front panels that can not be removed to insert things like
     powered front panel hubs and DVD drives.

     Proprietary power supplies with proprietary power connectors.

     Proprietary dimensions on motherboards (not ATX, ITX
     or anything recognizable).

On the bright side, Lenovo's Think Stations are pretty
reliable.  Just hope they don't break.

I have seen recommendations for Dell, but I have not had
great experiences will Dell in the past, especially their
habit of putting intermittent motherboards down the parts
cleaner and reissuing them a spare parts.

Anyone have a recommendation for a business grade
computers that use generic parts and are very reliable?

Many thanks,
-T