Leaded solder fumes are pretty harmless if that's a worry, the fumes are just flux which is a mild irritant and after long exposure might cause a slight cough, there's no lead in it, unleaded solder fumes are actually worse for you.
If you want a solder fume extractor though, which is reccomended as breathing them isn't a good idea anyway and I always get the smoke in my eye myself you can build one of these for next to nothing
http://www.thetonegod.com/tech/extract/extract.htmlNice looking build by the way, nice and neat board
If you want to build a Super hard on, don't stress the pot too much technically it should be a 5k C which is Reverse Log but you can use a 10 or 4.7 or 5k linear if you want, you can also get a 10k linear pot, put a 10k resistor between the 1st and 3rd lug and the taper of the pot will be biased towards being a reverse log.
Also you can try a 2N7000 rather than the BS170, some people prefer it.
If you wanna tweak a build why don't you buy a breadboard? Once you get started with one you can even start designing your own circuits let alone tweaking and they allow you to test a pedal without commiting it to a board, there's good info on it here
http://www.beavisaudio.com/bboard/For parts sourcing in America I only know of
www.smallbearelec.com but they have pretty much everything you'd need for a simple build, I dunno about pedalpartsplus though, they might be better for prices.
Be warned though... building is an addictive hobby, it should be classed.