The Five Fish kits, just make sure you add up the total cost including chassis and power supply. I can't remember the total prices. The 500 Series stuff is a great deal though, if you have a 500 rack.
The Seventh Circle Audio (
http://www.seventhcircleaudio.com/) kits are really good and sound amazing. The chassis and power supply are very solid and provides a great platform for expansion. You can do a single channel T15 (similar to the Five Fish SC-1's) for $399. Another channel is $89. These are just super clean.
So a bit out of budget, but IMHO very much worth it. Especially when you start adding transformer based pres.
Reality is that for transformers alone, you are looking at $125-$150 range. PCB around $20-$30, XLR's, pots, knobs, resistors, caps etc. So the kit prices are all comparable. Believe me, those guys aren't getting rich of the kits. Just the time it takes to source and order parts yourself and shipping will make it very much worth it.
I have essentially the same thing as the GAP from the Group Buy a while back. I was able to grab 2 TNC-84's and picked up a couple TNC-73's used. They have been great to me. Blows away any of my usual run of the mill pres.
Haven't compared to real Neve's, but I have compared it with the SCA N72 and SCA A12. It is N72-Esque... but falls somewhere in the middle between them. Little aggressive in the mids, but not as much as the A12, smooth on the top but not as sweet and rich in depth as the N72. But maybe a bit more punchy.
It is a colored pre and it does stack well. You can drive the hell out of the input and turn down the output to give it a totally different character. Even pull some grit out of it too.
I got mine for really cheap, plus the EQ is very useful and great sounding. At $300 a channel, I don't know, I think I would save and go for one of the kits. I still use mine all the time, but I think the kits could give you a better platform to expand later with different and great sounding options.
