Don't forget, if you decide to go with a spool or a welded front diff, that all the rest of your adjustments will go out the window.

Your driving style (brake in a straight line) and then hit all of your marks, is EXACTLY what you need to do with a locked front diff. In order for it to turn, you have to be on the gas.

I've been running a locked front diff for years, and have adjusted my setup and driving style to utilize the added traction that you get from both front wheels bitting all the time.

Like others have said, corner weights and alignment have a lot to do with you setup, and how you like the car to feel.