I am looking for a payment solution,that will opperate over  the web
as well as POS devices .The main aspect that I am looking at is the
ability to 'SPLIT' the payment into multiple parts,this being one
single payment, and Not Agregated. As an example, I would like to be
able to book a service for a customer. I would need to pay the
supplier, which could be multiple service providers such as car rental
companies, hotels,courier companies, my own service fees as well as
any commision that may be due from the service providers  The
main form of payment would be credit card, however other methods such
as debit card and check would be a bonus. This would need to be
acchieved with one transaction of the customers prefered method of
payment, be this credit card or other payment.
Due to the complexity of such a solution, it would be important to
have a robust reconsiliation facility.

Look into Paymentech; they connect to many shopping carts and POS
systems without too much work involved.  I am not aware if they have
the ability to split the payment however - I would just give the
company a call and ask.  CCBill has done split payment arrangements
for me in the past, however they do not have as many POS and shopping
carts on board as Paymentech does.

I have clients set up with Paymentech and Yahoo Merchant Solutions,
and other clients set up using Microsoft Retail Management System as
their POS and GemCart.net as their shopping cart, both running off of
the same Paymentech account.