[amsat-bb] Mast mounted Pre Amps? what to use?

I would like to ask the group what there thoughts are on Pre Amps? I'd like to go with an amp that is mast mounted and can handle some power through it.(auto Switching) I have the antenna system down right for some mods and with the sale of some other toys I have saved up for a good one. What are you using or would your recommend?

Thanks Marv N0FJP