I have a '69 Grand PRix 428 in my '68 bird (non-ac) and whoever installed the dip stick must have used a generic one and modified it to make it fit. So the tube that enters the block is crimped all around the end so it would fit. Similarly, the dip stick doesn't stay in position and is not secured.

I was curious if anyone has any recommendations for a proper dipstick and tube? And I believe for an install the oil pan has to come off, is that correct?

Yes the oil pan has to come off.
Depending on if your engine has a factory windage tray or not also will determine the lower dipstick tube you should have. Providing someone did not forget to install that.
The dipstick tube is installed from inside the block.