I don't see that a 45 really has any advantage, and they have one big disadvantage which is the fact that 90 percent shoot 50 cal so your availability and choices are very limited becase the other 10 percent is also split between 54 and 45. As far as I know the really good choices are the 200gr shock Wave and the 200gr Xtp and some 200gr sweged or cast bullet, there is also the Sabortooth and I suppose if nothing else worked you could try a Power Belt.
It would take several pages to list the varity of bullets and the different petal thickness and type of sabots for a 50.
I have all three but for a choice between 45 and 54 I would thake the 54 and use a 50 cal pistol bullet [which there are a number of brand and weights available in]in a purple sabot There are a couple others but the purple is the standard and the one I use. My normal load for deer is 140 gr RS and a 300gr Widner bullet it really puts the smack on a deer or bear or boar; when we get our buffalo hunt to gether I will use the 54 with 350 gr bullet.
But for deer the 50 is just as good, most of my kills are bangflops with the 50 and the 250gr Gold Dot.
Good luck and have fun what ever you choose ,if you are in it long you will end up with a couple of each like me and Sabotloader and Cayuqad. Lee