I had a cheap mic pre with a 12ax7 tube in it that I started using for a guitar preamp. It sounded a lot better when I got into buying vintage tubes for it. You can switch tube types within the 12xxx family. I found using a 12au7 Mullard tube made in the 50's was a good clean preamp.
I bought a Hafler T2 preamp off ebay that uses 2 tubes, one for a clean channel and 1 for a distortion channel.
So basically I'm recommending any real tube preamp and learn about the different tubes and how they sound (by buying them- school of hard knocks).
I have modern modelers but a lot of the effects on the Eclipse need a clean guitar sound to be heard properly.
Also give any quality mic pre's you have access to a try.