Every turbo has a compressor performance chart to go with it. Don't worry about whether it came from a gas or diesel, pick the turbo you want based on the compressor chart.

Also, running a twin turbo setup is not necessary. A single turbo is more efficient and will make more power. Twin turbos do spool faster, but modern turbine and compressor geometries have significantly cut back on turbo lag and the added cost of the twin turbo setup rarely offsets the reduction in lag over a single turbo. The main reason to run a twin turbo on a v8 is that it is sometimes easier to plumb, if you have the space for both turbos in the engine compartment. To run a single turbo, you will have to route all of the exhaust to one side of the engine compartment which equals an expensive set of headers. The twin setup also lets you run cast manifolds which work well with turbos because exhaust scavenging is no longer important, they retain heat (heat makes the turbine go around, not flow), and most importantly they have the strength to support the weight of the turbo.