Yes, the Tamagotchi Plus can connect to and marry any of the English Connections as it is basically the Japanese equivalent to the English V1. I have one and it's not super feature filled - the games, characters, etc. are all exactly the same as the V1.
I don't know about the regular Keitai as I don't own one, but the Keitai Akai is able to connect to English connections. They cannot marry, though, and connecting is limited to either gift giving or playing a random connection game. I'd still recommend the Akai as it's pretty fun and the characters are really cute.
The Entama/Uratama cannot connect with any English releases, only each other and the Keitai/Akai.