60db gain 100 ohm load phono pre

ifi zen phono

All that gain means is where the volume knob winds up. There's way more to a phono stage than dB gain. Way more. Shop for phono stages based on sound quality, or you may wind up with something that doesn't sound any better, maybe even sounds worse, but with the volume knob turned lower.

For your budget, check out the Parks Puffin. Plenty of gain and very quiet. 

You should be able to get a used Sutherland KC Vibe for about 500 bucks. It has all the adjustments (60db gain and 100 ohm) that you are looking for!