Since you don't seem to have a lot of experience, I would urge you to purchase something that is comfortable to your budget and in excellent working condition. If you are buying used, you should include in your budget some money for having it serviced. Khorns are insanely efficient and any buzz or hum will be exponentially more annoying than with a traditional box speaker. The Dynaco designs work well with the Khorn. I use MK3's and St 35's on mine and I have a few others (Scott 340a, Fisher 400, Decware SE 84, blah blah).