Horizontal bandsaw, but you want a swivel head if you are going to be switching frequently back and forth for angle cuts. Conventional horizontal handsaws the head is fixed and it is very awkward to set angles, let alone with any accuracy. I have a 9x12 Turn-Pro gear head horizontal, good for straight cuts but a pain to do miters. Also for short pieces w/o modifications not so good, it does poorly on angles not because of the cut but setting it up to do the angles accurately. Also time consuming to switch back and forth. Depending on your price range, a basic swivel head like a 7x12 run around 1500-2000, next level up would be the Jet (HVBS-710G, JET J-9180-3, J-9225) or Baileigh (BS-712MS, 210M, 250M), and then there is the the Ellis. There are previous reviews on this forum of all of these.
Another option that you will see in many metal yards for small stock iron is a cold saw/abrasive chop saws. These come in many variations from inexpensive manual all the way up to automatic, and priced accordingly. The basic abrasive type are loud and nasty, so if you are doing a lot of cutting in a garage or shop, not ideal. The disc size needs to be large enough to accommodate angle work in the dimension stock you want to cut. A few people have purchased the Ellis, I have used them and they do a great job. The price is also commensurate.
I studied bandsaws for 3 months and watched for used ones. Since I live in LA (Lower Alabama), Craigslist is almost worthless. The belief of the region is that used equipment is worth almost as much as new and the availability is limited too. I decided to give it up and "buy once" and got...
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If I were to do it again I probably would have gone with a swivel head, but at the time the price was right ($900) and I didn't have the space for a swivel head. If I routinely needed to do various angle and straight cuts, I would have gone with the swivel.
I have been dealing with Matt @ Quality Machine Tools for about a month and a half now looking at a new vertical and a new horizontal bandsaw to replace my previous saws. I have found very, very little information on the particular saw I was looking at, the Baileigh BS-210M mitered head...
www.hobby-machinist.com