Why? Most of my condensers require the gain at around half on my Presonus. The SM7B needs 75%, or to be honest a bit more, but above 75% the Presonus hiss starts to creep in, but I've discovered that in Cubase, if I pop the Cubase compressor in, and straight line the compressor so there is no knee, I can use the makeup gain function to get normal record levels and the overall noise is low enough to not be of any concern. I'm not sure what you mean by the preamp comment 'to bring the most out of it'? What comes out should not need modifying by the preamp in my book. Annoyingly, the SM7B is probably not the mic I have in the top go to mics in my collection. Close in, it's OK, more nthan a few inches and it's too thin and weedy and also seems very responsive to the room sounds. I loaned it to a friend who loved it, but had to get it back from him when I picked up a video client who wanted two presenters with that exact mic, because it LOOKED good. I had to actually buy another, so now I have two of the things - which I suppose might be useful at some point. They're also too heavy for my boom stands on full extension.
I'd rather have an excellent mic and a modest interface. I've not yet discovered a bad one. I know many folk bestow magical things on some preamps, but for me, they amplify, and get the sound into the computer. I can process it there. I'm never going to spend my money on the 'special' preamps, because I am happy with what I have. The Presonus has plenty of inputs and outputs, and the Tascam is now in the other studio, still doing a great job.
If I want a mic on a voice, my old goto mic was an AKG 414 but that's now replaced by a TLM 103 which I rather like. I'm lucky enough to have a decent mic collection going back years, but my favourites do seem to change. The ones that don't get put away still mean the SM57 is a good choice - and it was a 57/414 sitting in the studio permanently out, and the 414s now replaced. I've got some double bass recording to do sometime soon, and I've never tried the 103 on a DB, but maybe I should try the SM7B? In fairness I bet the 57 would be pretty good.