For your first kit get something that if you make a mistake it will not be super expensive. A WBP Polish or a nice Romy on a Nodak spud.
Do you have any build tools? Have you read up on the process or watched any of several videos on the subject?
If you want a nice Russian kit you could match it with a Polish barrel, Childers receiver and send it to a pro builder.
There are of course other options but as we type these are growing fewer every day.