I've never used a halogen oven, but the three things to look for are:
1) a temperature dial you can adjust freely. My oven only adjusts by 25 degree increments, and if 275 had not turned out to hold just below 300 (I use Kato clay and that's my preferred temp), I would have had to return it.
2) make sure there's room for a separate thermometer. I like the "probe" type and had to get my hubby to snip a tiny notch in the door for the cord to pass through so it doesn't hold the door open 1/8".
3) that there's enough ROOM in the oven (height, width, depth) to hold your preferred size object. If you only make beads, this may not be an issue, but I wanted an oven tall enough to hold a 6" tall sculpture without putting it right up into the element.