I have no advice really as my chest freezer is sitting in the basement waiting until I could get an electrician in to put a plug in for it but my vote would be for upright.
I'm the type of person that if I put something in a drawer, I forget it was ever there and it would be just a waste of food for me.
I do not like chest freezers. I'm short with a bad back, so leaning over for 10 minutes sifting through meat, trying to find the roast I'm looking for is no good for me. I much prefer the upright, which is easier for me to go through.
I think the 14 cu. ft. ones tend to be big enough for most peoples needs, but if you buy in bulk a lot, or bag any deer or anything like that, you'd probably want to go for a 20.
But freezers are right up there with politics and religion in my family - everyone likes something different and is super opinionated on what they love, lol. You couldn't get my sister to part with her chest freezer, but I'd rather shank myself in the face than try to find what she sends me down there for, lol.
I answered in cocktail, I know, but I have an upright and prefer it. I did NOT want a chest freezer. Plus uprights take up less floor space, which is at a premium in our house.
You do have to defrost them from time to time though.
I am not sure how big ours is. It isn't terribly large, but it is good for us most of the time.
Ours is a 7.0 deep freezer. I hope our next is an upright. This freezer is over 8 year old and I can't imagine living without one. I cook/buy in bulk and the upright would be better for organizing. It's impossible to keep my deep freezer organized. I guess I have a love, hate relationship with it.
I have two large uprights and would never, ever, ever buy a chest freezer. I've dealt with them on ocassion at other people's homes. Pain. In. The. Butt.
As far as size, it depends on how much you intend to put in it. Like I said, we have two large freezers and keep them about 2/3 full most of the time. But I have a large family. I also like to stock up on things when I hit good sales and I store water in one for trips and hot day excursions (we have ice water for hours!).
The only drawback with uprights is having to defrost them occasionally. If you're careful with how often you open the door, though, you don't have to do it often. I've had my older freezer for nearly 10 years now and am just now thinking I should defrost it sometime in the next year for the first time.