You'll need to have seen Suicune in all of those locations before it will appear on Route 25 for you to fight.
Happy playing ;D
to find Blue in HeartGold or SoulSilver go to Cinabar Island next to Seafoam Island and go right next to the Pokemon center.
You can go to game stop and they have it for $ 30.00
you go to the marsh area
go in
If you go to Kanto you will find plenty of Oddish.
Vulpix is not available in HeartGold. You can, however, find a friend who has SoulSilver that will be willing to trade with you, or you can go on the GTS
You can't go to Hoenn in Pokemon HeartGold. You can only go to Kanto.
you have to go back to your moms house
You have to beat Red then go to Mr. Pokemon's house then he will give it to you.
To get hippopotas in heartgold and soulsilver you need to go to safari zone and use special items.
Go to Serebii.net go click the pokedex link and then find the Pokemon you want and it will give the location of that Pokemon.
finish the mr Pokemon thing for elm and go see your mum she will give it to you