Suggest me the best PSU?

Pick a tier 1 unit from a list such as this:
https://community.newegg.com/eggxpert/computer_hardware/f/135081/t/45344.aspx?Redirected=true
sli titan x will want about 850w, but I might buy more.
Here is a Seasonic X-1050
http://www.newegg.com/Product/Product.aspx?Item=N82E16817151110&nm_mc=KNC-GoogleAdwords-PC&cm_mmc=KNC-GoogleAdwords-PC-_-pla-_-Power+Supplies-_-N82E16817151110&gclid=CL7Ot-qm9csCFRNZhgod5n8KjQ&gclsrc=aw.ds

No doubt you are looking at a top end build.
Is this for gaming, or batch production?
Do you have a budget limit?

Likely you have not picked the best options.