There are hundreds (if not more) of type case layouts. Most of the cases we have in the studio are California Job Case layouts. Originally, cases were divided according to upper and lower case, but the job case combines these two cases (so that you can complete the 'job' with one 'case').
There are numerous places to get materials and supplies in the Twin Cities, including:
Northwest Graphic Supply
4200 E. Lake St. in Minneapolis
Open Monday-Friday, 8:15a-5pm
There are several companies in the Twin Cities that do commercial polymer plate letterpress, including:
The following resource shows some examples of this process in contemporary design: