Well, if MOST of the panels are narrower, then maybe an open ended one is fine. Even an open ended sander is still about 10 times faster than all by hand. I have used a woodmaster drum sander and liked it. Also used a Performax open ended sander, and while I certainly had complaints about it, it still did a lot of work for me. If i had any quantity of wood to sand, I would certainly use the drum rather than hand sanding. On the other hand, if you are really sanding a lot of wood, (and I would guess that you aren't yet, as you are still hand sanding), then consider a small wide belt sander. Steel city makes a really small one, that is probably not too expensive. It probably is somewhat between a wide belt and a drum in speed, probably closer to the drum. A small widebelt, like the Sunhill PDM15, certainly is much faster than a drum. But you can buy a drum sander for less money. If you have LOTS of space, you might consider a stroke sander. You can buy them used CHEAP, and they are fast and do a nice job. If you are sanding mostly softer woods rather than maple or such, then a drum might be the best. If harder woods, and a lot of it, then maybe a wide belt or a stroke.