Get any Hoenn starter you want. It doesn't matter.
Get a kanto starter :p
In Pokemon Heartgold and Soulsilver you can get a Johto starter from Professor Elm, a Hoenn starter from Steven, and a Kanto starter from Professor Oak
In Pokemon Emerald, when you complete the Hoenn Pokedex, Proffesor Birch gives you a Johto starter. In Pokemon HeartGold and SoulSilver, after defeating Red, Professor Oak will give you a Kanto Starter and Steven will give you a Hoenn Starter.
once you defeat red in mt. silver he will give you a kanto starter.... After that you should go to saffron city in the silph co building and he will give a hoenn starter on the colour stone you choose.
Getting the Hoenn Pokemon is completely optional. Therefore, there is no chronological event that is placed after getting your choice of Hoenn starter. Just try doing some other extra events.
You cannot actually go to Hoenn in SoulSilver, but you can catch Pokemon from Hoenn on Wednesdays with Hoenn Music on the radio.
You cannot go to the Hoenn region in Pokemon Heart Gold and Soul Silver. Just because you get a Hoenn starter from Steven Stone (Hoenn League Champion) doesn't mean you go to the Hoenn region.
You can catch every Pokemon, you can do the arceus and groudon events, you can Get a kanto starter from professor oak, a hoenn starter from steven at the silph building, you can catch mewtwo
You can't go to Hoenn in Pokemon HG/SS.
No, you cannot go to Hoenn in Pokemon SoulSilver, but you can still get the Hoenn legendaries. Pokemon SoulSilver is a copy of Pokemon Silver, and you can only go to Johto and Kanto.
You get a Kanto starter, unlock Groudon and Kyogre, if you go to Silph Co you get a Hoenn starter, and I think that's it.
He is the Hoenn Champion. But he isn't in Soul Silver for a battle. He'll tell you that Latios is roaming Kanto. He let's you have one of the Hoenn Starter Pokemon. He also let's you trade with him.