Brother and I have been doing a little looking and for a 200 size you pretty much need a lowboy with outriggers to haul. A 160 you can get by with a standard trailer with ramps I think.

CAT, Deere(Hitachi), Komatsu, and Case(Link Belt) all make good machines. I was surprised to hear the price of hyd thumbs. New ones can run up to nearly $15k for the progressive ones that open and close all the way.

CAT numbers would be like a 316/320. Older Deere are 490/690 and newer are 160/200 for that size range. The others all go by that 160/200 numbers. Different letters signify newer series. I think whatever you get, you want to make sure to get a long undercarriage which is usually designated by "LC". I've been told the ones without are the ones you usually see on the internet buried all the way up to the cab. You may want someone experienced to look at the tracks to make sure the undercarriage isn't worn out. The sproket teeth will start to get sharp as they are worn. The rollers will also start to rub on the pin heads I think. Salesman claims in this part of the world the undercarriage will often times last nearly 10k hours. In other areas they can't make it more than a couple thousand due to sand, etc.There are a lot of them listed at www.machinerytrader.com