Preamp match for my First Watt F-7 amp.

numerous preamps/linestages should work

nelson pass' fw amps have somewhat low gain/input sensitivity for modern solid state power amps, so make sure the model you choose has plenty of gain and low output impedance

There is a Supratek Syrah on US Audiomart that would do the trick if you can convince him to ship or make arrangements to pick it up.  Has gain of 26db at max setting.

Any suggestions at around 1000k...

You should be able to find something decent with that budget.

When you say "decent sound", do you mean adequate volume level, or do you mean that the sound is otherwise unsatisfactory until you hit a high volume level?  What I am asking is if sufficient gain is your only concern.

If what you seek is more gain, this seems a bit odd because Quicksilver linestages have something like 18 db of gain, which is quite a lot.  I cannot think of any situation where that much gain would be exhausted before one hits a level that would cause any amp to clip  But, if your source is a phono setup that doesn't have enough gain, that is a possibility. In that case, you should be looking for a phono preamp, not a linestage with more gain.

I cannot think of any situation where that much gain would be exhausted before one hits a level that would cause any amp to clip 

I was thinking the same thing. Is the preamp getting enough voltage?