it's easy to modify a li'l chopper banana fletch for both a lower length and profile. you could use either the standard or hi-pro banana choppers and simply double stick tape on a new quill fence made from most anything, including thin cardboard (which might be one of the better materials).
there are more than a few benefits from using a four inch 4-fletch, including getting two fletches from a single full length feather (for chopping or burning), no need for nock indexing, the same or larger effective fletch surface area, lower profile feathers are stiffer and more durable, and *possible* greater shelf/plate clearance of lower height fletches.
as to the 4-fletch configuration, it doesn't much matter. i've tried them all and prefer the 75x105 as it offers nearly the same large fletch angle spread as a 120 degree 3-fletch. with lo-pro fletches, you won't notice a difference even if 90x90 is used.
though it works fine, too, i never could get used to the 2-fletch look of the 60x120 4-fletch
however, that would yield the most effective fletch clearance in a lo-pro fletch format, with maximum effective guidance.