Personally I mainly use Astra Implants which I find predictable and long lasting. I like a titanium surface which is roughened by subtraction and surface active. The Roughness should be full hieght and and micro thread at the top end to evenly load bone and maintain long term bone (and Gum ) hieght around the fixture. The internal should always be a cone fit to reduce abutment scres stress.
The best abutment and crown depends on balancing aesthetics and the loading in the UR4 region this is variable as it depends on your actual bite and the width of your smile.
For a free initial assesment call Amy 0121 643 0610 and I should be able to give a more specific response in your case.
Rob