BT139 looks like:

I want something like similar, but all case cover by plastic insulation.

 

I read that it is BT139x/BT136x triac.

Other similar triac names easier to find ?

 

Hello,

When you look at ebay, you will see them from hong kong or china, wich gives me no good feeling.
You might want to look for the BTA41, wich is the isolated version of the BTB41:
http://www.newark.com/stmicroelectronics/bta41-800brg/triac-800v-40a-top-3/dp/89K1246

Bertus

 

Here is the datasheet from Mouser

 

BT139 looks like:

I want something like similar, but all case cover by plastic insulation.

You want a SOT186 package.