Let's see if I mention other kit providers i might get in trouble here, so I will be generic and say there are a few kit providers in US. I remember Doug Hendricks once giving a specific progression from simple to more complex, to outfit a qrp station.
A digital keyed is a nice start. Few parts, no toroid.
Then another accessory or a simple receiver.
Maybe a manual antenna tuner, yes a nice one at 4 state as well as above items.
I would progress to a simple transceiver, but watch complexity the most popular one now sold from overseas I suggest may be too challenging until you have built some others.
Test equipment kits seem too scarce now.
Enjoy your progression, don't lament what kits are extinct since there seem to be opportunities still.
73 curt wb8yyy