Tips on dealing with bulky/irregularly shaped pieces in drill press?

if you still need to buy the drill...why not buy a magnetic base one?
you just set it on the mounting flange, and as long as that isnt warped it will be dead plumb on the bolt hole

then it just become a matter of securing the mainfold in a vice or whatever, but the angles will no longer matter

you can even get em at wallyworld

https://www.walmart.com/ip/JANCY-06...001195&wl14=magnetic base drill press&veh=sem