Good tube amp kit for sale these days

I would go with Bob Latino's ST-70 kits from tubes4hifi.com
They are new Dynaco ST-70 kits with improved chassis, connectors, and the VTA driver board. They're switchable between pentode/triode operation, and he also makes more powerful versions (ST-120 and M-125 monoblocks). It's a good way to get into the kit/amp building world as he provides great instructions. I would personally go for the ST-70 and work it for use with EL34's instead of KT-88's. The EL34's will give you more of that "tubey" sound. If your speakers are incredibly power hungry make the M-125 monoblocks. They're actually easier to build but would cost more.

If you want to start off slightly cheaper and simpler, Bottlehead makes a little tube headphone amp for a bit over $200. If you have have really high efficiency speakers (98db+), you could build their actual power amps, but I haven't actually heard those.

I have two ST-70's myself. I'm currently using a fully modded Curcio ST-70. While I really like the sound, the only thing it really has in common with the original is the transformers and the chassis. It's also just about the most complicated mod that's out there. The VTA ST-70 from Bob Latino sounds really good, and I'm actually considering ordering one and building another myself. Bob is also quite helpful.

Budget? Speakers you intend to drive?

For low power SET look at Tube Audio Lab. I built one of Min's amps (he supplies parts and case) and am very happy with it. I built a 2A3 amp but he has others as well.
For a kit I built the Elekit TU879 that puts out 9 watts with 6L6 or EL34s. Comes with everything except solder. If you buy, get it from Victor at VK Music, out of Canada he is the NA distributor (assuming you're located in NA)
For a lower cost but lower power amp look at Decware. I built the ZKit1 that
puts out a few watts with EL84s.

I highly second the recommendation for Bob Latino's amps. I've built both the ST-70 and ST-120 kits. They are a joy to build, lots of fun, and the directions are superbly written. After you finish the amp(s), you'll have a great sounding piece of equipment to use.

Hi all ! Just recently built a 4 wpc amp from Transcendent Sound...easy build and sounds great . Just ordered a pair of 300b mono blocks from Bottlehead . Should be an easy build and seems like great value for the money . If you need more power the Bob Latino stuff looks good . How much power do you need ?