If you can do with a really low-powered amp, there is the Elekit 300b amps. I've heard that amp and it is quite good for the money. It is supposedly quite easy to build because it comes with clear instructions with a lot of useful illustrations (very important, particularly for novice builders).
ANK Audio Kits make a large range of electronic kits that are based on Audio Note (uk) electronics and might even use parts sourced from Audio Note. I don't know how good the kit versions are compared to the real deal, but the real deal is very good.