Comment on your 3 scenarios? Well for starters, microphone choice makes more of an impact on sound than preamp choice does IMHO. Other posters have stated mic is 90% and the pre is 10%
I would think it's more 75-25 in ratio and when you add a nice comp like an 1176 or an LA2A or an API, then the ratio becomes more 70 mic, 10 comp and 20 pre.
Ok, getting back to microphones. I'm puzzled with the sm57s on toms. That's a sure-fire way to make them sound like old fashioned ice-cream tubs. I don't know of any pre that will save that scenario without extensive EQ and by that time, you would just be wishing you had 3 MD421s anyhoo...
And a c1000 for the hats? Sure, I guess so... I've had moderate success with c1000s as cymbal microphones (mais, a chacun, sa meme) but then you have your u87 as outside kick microphone, indicating that's the most important part of the entire kit sound to you.
I would rather have a mono room sound with the U87 than have a stereo room/overhead sound with cheaper microphones. That's where the bulk of your sound should come from.
Just my opinion, others will vary.