potty training

so what to get. they spend most of their time down stairs and our bathroom is upstairs. I was thinking of buying 3 little potty seats and 1 that goes on the toilet. So they have a set down stairs and a seat and a potty in the bathroom.
Does this make sense??

What do you recommend. and yes I am thinking ahead of the game. They are 18 months actual, but I thought it couldn't hurt.

potty training

I bought potties a while ago when my girls started telling me they had peepee or poopie diapers. I bought the potties at BRU that turn into stools. I hate them LOL Each potty has 4 different parts, the base that turns into a stool, the seat (which can also be put on the toilet), a piece of foam that sits in the seat and a receptical to catch and dump the pee. They are constantly taking them apart. If I thought better about it I would have forgone the versatility for less parts. I am at the point where I am going to just buy other simpler potties and later on use these for the toilet seats and stools.