Engine/Transmission (1994 - 1998) twin turbo selection

[SEmerson]

I am looking at a twin setup. I have a hx35 and a hx40 to use. What would be a good secound turbo? I was thinking of running the 35 now and can switch to the 40 later if needed. I drive empty most of the time. But I also need to be able to tow. I added a snow stage 3 but I can still peg my pyro.