You are going to stay with round instrument?
Dittel KRT2 - a friend fitted one for 833 upgrade. I find the display a bit hard to read in sunlight (and it failed already once and had to be replaced also) and handling is not my favorite, but it is the most affordable one on the market (you can find them for <1.000)
Funkwerk ATR833 LCD, Funkwerk ATR833 OLED - nice little fellows, I used both in some charter planes, but was not impressed by audio quality. They have a reputation for not very good transmit/receive capability, but I have not experienced that.
Trig TY91 - my favorite from the list, nice display, great audio, quite ok to handle even with gloves
Becker ATR6201 - one of the classics and on par technically with the Trig, most of the times a tit more expensive
One more to the list: MGL V6 - probably the most affordable way to get 833.
If you are going to fumble at the audio panel and have an N-reg or experimental, the PAR200 from PS Engineering is another hot candidate, as it is an audio panel driving a Trig in the back (and Gear of the Year 2014). Unfortunately it is only FAA TSO'ed and they struggle since almost a year to get ETSO - no idea when this is coming, yet.
Last edited by ChickenHouse; 13th Aug 2014 at 14:25.