[slickshift]

Bells and whistles, no, but those de-spec'd HD pieces of crap will vibrate your hand off your wrist by 10AM coffee break

Porter-Cable or DeWalt from a Tool Store should do it

I'm not surprised to hear recommendations of Makita either
I've not used a palm sander by them, but many other tools that were all great

 

[slickshift]

...a Dewalt orbital ...There may be one out there with a more compact design...

They've got a reasonably compact one that is extremely comfortable

 

[slickshift]

Well, really the best thing to do is go to your local Tool Store and try them out

Sounds dumb, but seriously, it's the best way
You could be using this sander for hours at a time, make sure it's got good weight and balance for you

If they won't let you actually use them, at least hold them in your hand
Upside down, against the wall....
(you can make the buzzing noises with your mouth...lol)

If you don't like the feel of it, it doesn't matter how may people tell you it's good, you won't want to use it, you'll fatigue early, etc....

You'll have to decide about 1/4 sheet or round sandpaper
If you've got nothing, a 1/4 sheet would be a better first one, as the round can't get into some areas
You can get the round one later
Then there's hook and loop or adhesive...