Edouard?

Eduard (www.eduard.cz) is a Czechoslovakian company that makes photo etch (PE) parts. These parts are paper thin and made out of brass. They add a lot of detail to some kits that aren't well detailed. If the 3 kits you list above are Tamiya kits, the Leopard 2A5 doesn't really need it. That is one of the nicest modern armor kits available. If it is the Italeri kit, the choice is yours. If the T-34 is a Tamiya kit, no PE in the world is going to accurize it. There are several better kits of a T-34/85 on the market that would run less than the cost of the Tamiya kit + PE. Gepard is an older kit as well so again the choice is yours.

Go to the Eduard site (see above link) and search for the PE set for your kit. You can then access the instructions for that particular set to see if it would be of help to you.

Eduard is the most popular but you've got also Aber, Roar,Verlinden and may be some others.

piwi is right, the others are very good as well, particularly Aber. The advantage with Eduard is the color, they have a gray sheen that looks like steel rather than brass, that helps if you happen to rub the paint off a little.

The benefit to Eduard is that they cover all types of vehicles and eras. Aber tends to do just WW2, mostly German and some Russian. Aber is the best though their sets are outrageously complete (working hinges).

Agreed Aber is the most detailed and complex out of the Photetched companies. I like The SHow Modelling if I can get my hands on a particular fret.

I usually limit my Aber photetched to grills and screens, and some other stuff. While I rather save my self the sanity of making one of Aber's complex tool clamps and go with Eduard 2 part or 1 part clamps.