I would recomend Oehler 35P.......but they are not makeing them any more.
like others have said, Any Pact will do.

I have the Pact model 1 as well.
My dog chewed through one of the cables once (I replaced it) and when the rechargable battery died I soldered in a jack for an external six volt battery so I wouldn't have to buy that special battery. One lantern battery lasts about a year. No more recharging for me. I can spend as much time at the range as I want without having to plug it in to an outlet.
I too, like everyone who owns one, have never had any trouble with it. When I first got it I compared it to my older Oehler for accuracy and the difference is less than shot to shot variations. It is much more portable and easier to use.