Fuel pump questions

[4seasons69]

Okay I've been playing with the idea of switching fuel pumps. I kinda want to make sure I don't run out of fuel pump on the dyno when she's getting tuned. Now I have ford gt pumps which are basically not much better than walbro 255s.

Now onto the questions. How much power do you guys think these pumps can support?

I've been looking into the walbro 400s but have recently been finding info that these are gas only pumps and not to use them with e85? anyone know how they would handle e85?

Now the walbro 450 is the e85 version of the 400 quite a bit more expensive but seems to be one hell of a pump. Now my question on this is with dual in tank pumps can you run a larger pump and a smaller pump? Or will will the larger pump overrun the smaller pump and make the smaller pump not effective?

I ask this because I don't think I would need the fuel 2 450s would supply and for the price of two 450s I would just get a boost a pump instead

Also anyone have any experience with dw300 or aeromotive stealth 340 pumps? My next idea was switching to twin dw300s or stealth 340s

Any fact based info and opinions are appreciated. Sorry for rambling lol.