Can certainly vouch for Chrome Prince as far as after sales help goes, he has a comprehensive product and is always available to help you with anything.
As far as adding things of your own go, I can't see that being a problem as he designed and programmed our own database from scratch which is fantastic!
His pricing for "extras" is extremely reasonable and his patience with continued requests from us for extra things and changes to our setup is first class.
Would highly recommend you to contact him, we will certainly continue to use him for ongoing work we have.

Merry Xmas, hope you all find a winner today!