Other than my home built unit the best I have heard or seen is my friends ICO TEC gc500. The remote we have used out to 260 yards, holds 200 free calls and cost less than $175.00 most places. It is compact battery's life (use good batterys) is very good, screen lights up well at night and easy to read too.
http://www.icotec.com/gc500-call/
Al