KeithT,
If you're considering a singles gun only take a look at the Kreighoff KX5 with adjustable rib and comb as standard equip. Non removable trigger is the only drawback here. (built into the receiver) Costs run from around $4000 used to $5000 new cased. Kolar TS (trap single) offers the same equip., adjustable rib, adjustable comb and adjustable trigger shoe for about $6500 new and usually you can find one used on here for around $5500.00 cased. Kolar offers a dropout removeable trigger. I own a Kolar combo and they're bullet proof. Without a doubt and hands down the BEST customer service on this planet.
Good luck with your selection.
Dave