In general, cw kits tend to be more common. QCX plus is an amazing single band cw transceiver. Qrplabs also has other kits.
In the US, qrpguys, qrpkits, 4stateqrp also have kits. Also kc9on and w8diz. Look around before deciding what you will build first.
Bitx and ubitx were offered as preassembled boards, now just ubitx is offered. Unique now to have a simple ssb rig. Many customize their ubitx with fancy displays, processing and other mods.
Amateuradiokits.in supplied enclosures for many of our earlier version ubitx. their bitx seems new.
Do look around at all the kits available. All modes can be a blast, but cw is rather special.
73 curt wb8yyy