I've been assmbling a kit tube amp from S5 Electronics, a small, 8w 6 tube integrated that lives on a piece of wood, the KL8
Instructions are not the best but suffice to get it done (there is one missing figure and at least one missing step involving the input jacks but you can figure this out easily by the time to get to that stage of assembly). All you need is basic soldering skills (nobody's are more basic than mine), and the final assembly looked like this:
Despite their 86db sensitivity, I managed to drive my old Kef 103/2s with this to really pleasing room filling volume. At the very least, this kit tells you what you can achieve with a small investment in decent enough parts, a predesigned schematic and some labor. Sure you don't get anything that looks too good with this kit but you can begin to appreciate how more expensive transformers and caps might improve matters. There's a whole range of DIY forums out there to help (check out, for example, this one )
From here, I plan to move on to another kit, the Elekit integrated which comes from Japan complete with a decent chassis and ultra cool looks. In fact, there are more high quality kits out there than you might imagine and I suspect one could create a really decent amp for a reasonable investment. More as I go.