I get the feeling you don't want to divulge the exact specs of your turbo, which is fine, but the obscurity is going to reduce the quality of this discussion.
I saw that you have your 350/200s up for grabs, which makes me think that you're switching to a larger injector...
FWIW I am running a s475/88 with a 96mm inducer for the turbine (not 100% sure on the exducer size of the turbine :doh

with a 1.15 housing. I have the wheel clipped for protrusion and the mwe machined out on my 2.6 cover. I rarely use the 3.0 cover, less a few pulls a year, but I don't see much of a power gain with it on anyways. It runs very nice when hooked to a sled, but not so much on the street, it's a smokey pig which is why it never sees street action anymore. I've considered going with a larger exhaust housing, but I'm almost positive I'd fall under it at the end of the track leaving me with no spin-out, and I don't want that.
Just my experiences, hope this helps with your decisions....