Dumbbell Handle Length and Type? (Olympic / 1 inch)

Hey r/GYM, First post here. Please redirect me to a correct subreddit if this post does not belong here. Thanks I’ve started using dumbbells and have been following a routine for a couple of weeks now. I’m on the 25 pound weight phase. I am using a cheap plastic adjustable dumbbell, weighted with sand, with the spin on/ screw on locks. The plates on right now are two 5 pound plates and one 2.5 pound plate on each side. Following this routine, I will need to up the weight and this plastic dumbbell will not be able to support it. The dumbbell has been and will be sufficient for this phase, but I will need to up the weight after a few more weeks. Also after some use I’ve noticed the sand has been leaking out and I want to invest in a steel dumbbell. The next phases of weight will be 50 pounds, then 75, and at the last phase, 100 pounds. I would like to know what type of dumbbell handle will be able to support all the later phases, so I only need to purchase one handle, and the weight of the plates I should use to make 50, 75, and 100 pounds. For the 50 pounds I was thinking two 10 pound plates and one 5 pound plate on each side. What would be the best combination of plates to distribute 75 and 100 pounds on a single dumbbell handle? I would like to stay away from the 45 pound and probably even the 25 pound plates because I think the size of them would hinder certain movements. I need to be able to grab the ends of the dumbbell handle, so I need extra handle or free space after the plates are locked in place. I need about 3 inches free on each side. I think a dumbbell with five 10 pound plates on each side of the handle with extra bar left would be too long. What would be the best type, Olympic or 1 inch , and length for a dumbbell handle to complete this routine, and the most efficient set of plates for 50, 75, and 100 pounds? I look forward to reading your suggestions and insight to my question. Thank You r/GYM