For starters, since this is your first "public" appearance ... let me say .... Hi Austin !! . Welcome to IAP !!
For each of those gorgeous blanks, I would recommend a pen kit with a single "very" long barrel.
The one that comes to mind is the Artisan Clicker from CSUSA. . Here is a link to it:
The single tube design of the Artisan® Clicker Pen Kit not only emphasizes the natural beauty of the wood but also offers the look and feel of a traditional click type pen. Parker® type ballpoint refill Specifications:Finished size: 9/16" x 5-5/8"Minimum blank size: 3/4" x 3/4" x...
www.woodturnerscatalog.com
In my opinion, you should cut the two ends off each of the 3 blanks so that the remaining (central) portion matches the length of the brass tube in such a way that the blank pattern center corresponds to the lengthwise center of the brass tube length. . In other words, the blank pattern will be symmetric on the finished pen.
Hope that gives you an idea of what I have in mind. . Of course, the decision is up to you. . But it would be nice to use as much of the blank as possible on a single pen to show off the beautiful blank.