The box your dies came in should say what shell holder you need on the lablel. Also, what kind of dies are they? Carbide (grey box) or carbon steel (green box). If they are carbide dies you won't need the case lube. Anyway if you need to lube the cases, Hornady's One Shot IMO is a better lube and less messy.
I second the W296 powder for the 44. Also the hand primer and some large pistol primers. Of course you will need some bullets. I use Hornady 240 gr XTPs. Cast bullets are good for practice but if your velocity gets above 1000 fps you may have lead fouling issues if they are not a hard alloy.
The trimmer can wait. I've never trimmed any of my 44 brass. But when you get to loading rifle brass that's another story. A good trimmer is the RCBS Trim Pro.
Another bit of advice when you start to load, set your expansion die so it only flares the cases enough to start the bullet. Any more will result in shorter case life due to neck splitting.
Keep the questions coming. There are plenty of guys here willing to help out. Although alot of us have different views on powder selection, trimming cases, primers etc. so you will have to weigh the differences for yourself.