I cant really answer your questions with any authority, you need to speak to an expert to make sure everything is 100%, demon tweeks have been pretty helpful in the past.
You need to know the central bore of the wheels you have bought, if you are lucky they will slot straight on, if you are unlucky the bores will be smaller and will need to be drilled out, by an engineer!!!! If the bores are larger you need to find spigot rings that reduce the bores down to the correct size.
Regarding the bolts, I have no idea if yours will fit. If they are designed for alloys I guess they might be ok, remember though; if the hole in the wheel you put the bolt in is tapered (gets narrower as it goes in) or is just a straight hole flat to the surface of the wheel then the wheel bolt will need to match this profile also.