Thanks PB! I chose DirectX since it is better supported and documented in Visual Basic, along with just personal preference. Using Visual Basic already limits me to just the Windows OS, so the cross-platform ability of OpenGL doesn't help me much.
As for lines of code - I believe there is about 50,000 lines of comments and code (probably about 20,000 to 25,000 lines of code) total. Doesn't sound like much, I know - it surprises me, too. But I have removed and rewrote so many functions to speed them up and make them better, so a lot of what I have written has been written multiple times. This project has been an on-and-off project for me for about 8 months, then hte last 4 months I have been working on it a lot.