I have an s5 turbo engine and want to upgrade the turbo so i run low 11's what turbo should I get

 

The main question is how much do you want to spend ? .

You can run a hybrid like the bnr stage 3, that will make very good power. ( somewhere in the 310-360 I believe ) .

Its one of the simplease ways of making big power, but even that way there is alot of items you need to purchase to go with that.

example:

Injectors ( 720 -1600 or 550-1600)
fuel pump ( walbro )
intercooler
EMS Stand alone to control fuel and ignition : something like haltech e6x or atleast ! Rtek 2.0
new fuel filter ( to change old crusty one )
new oil and oil filter
new spark plugs
some kind of AI injection ( optional )

Now if you wanted to have bigger power, you will probably have to spend a bit more example,

new manifold
new turbo ( the To4R very well priced and makes stupid power )
new wastegate
new exhaust

plus all the above

If you also use the search option on this site you will find lots of good options and answers.

Welcome to the forum.