Ok, I'm not liking the look of the seven-string sets that are available, in terms of being able to use as a six string as well. I'm thinking of buying heavy six-string sets and then a seperate heavier string on top as a B-string.

Would it work if, say, I strung a D'Addario heavy gauge set (12-54) on the first 6 string, then took a 59 and used it for a "low B"/7th string?

My other option I'm considered is to get, for instance, the Medium top/Heavy Bottom (11-56) and either take the 59 as a B string OR push the 56 to the B string and get a 50 or 52 string in as the 6th string.

I noticed in both cases that the 5th and 6th strings in the sets have a fair difference of size between them (the HG's being 42 and 54 and the MTHB's being 44 and 56). Would having a string in the middle that's less than half that size difference between the two (or in the case of adding the 7th, the one above it) **** with the feel of playing (like the introduced string feeling tighter than the two around or under it)?

Sorry if this is really confusing, but it makes sense to me. Would appreciate some guidance.
You could do either. Buying a 6 string set that is the gauge you like for the top six strings and an extra single string for the low B is the intelligent way to do it because you get exactly what you want. It's what most guys did when 7 strings first came out and 7 string sets were as rare as fresh dodo eggs, it's how I used to do it.
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