Ok my kids ( 7 & 9)have discovered Lego games (indiana jones, harry potter etc) but trying to control the games via two player on my keyboard is heading towards a homicide

I was thinking of getting a cheap controller or two, but i can't make head nor tail of what the deal is with using them, will a cheap/generic controller work with Steam games that support controllers, or do they have to be a specific type of controller.

Note cheap for me is under $20- $30max for both, mainly because my kids will probably lose interest.

I have looked at the cheapies like these (and yes i realise they won't last forever)

http://www.trademe.co.nz/Browse/Listing.aspx?id=1010076975

or this

http://www.trademe.co.nz/Browse/Listing.aspx?id=1010207804

although these look like overkill

https://www.bidbud.co.nz/1013080098