issue with creating a 100x50 Matrix prop.

[Box on Rails]

I am trying to create a 100 x 50 Matrix prop in the preview that has 5000 total pixels. I have tried using the Vertical-Quad and the Vertical-Rectangle shape to make it and both will not create the 100x50 set up I need. I am wanting the set up to start at the bottom left and each string will have 150 pixels that will cover 3 columns each string. all strings starting on the bottom.  So when I go to set up the prop, under shapes, I have the 2 choices mentioned above to make the 100x50 matrix set up. I have set up both this way: 34 strings, 150 Nodes, and 2 folds. But this gives me a 102x50 set up. So I try to manually set up the 34th string to only have 50 pixels and there is no way to edit one string down from the default 450 to 150 circuits. I know that I can change the number of pixels per string to get an even number to make the 100x50 set up but I want to use 150 pixels per string. I have found that 150 pixels function well using a Pixie 16 with out power injection or adjusting the dimming curve. If I set the strings at 100 then I would need 3 Pixie16s.  I only have 2 available right now. So here is how I want the set up to work: for the first 32 strings (2Pixie16s) of 150 and then I would use a Pixie 2 for the remaining 2 strings and set the final 2 strings to 100 pixels each. So how do I adjust string 33 and 34 in the prop to have the end circuit show a value of 300 and not 450?