I was asked to make a three layer birthday cake with the top one being cheesecake any ideas

Well, what's your question?  

Would I take the order?  No, but I detest cheesecake.

Will you need to observe careful food safety rules/handling with the cheesecake?  yes

Will you need to give specific written instructions to the customer regarding the cheesecake?  yes

Will the weight pose problem for the support system?  Probably not if done correctly.

could you be more specific? on construction or recipes or how to stack or??

i used the cake mix doctor's melted ice cream cake to go with cheesecake -- this makes a rich dense cake that holds up well to cc -- and matches it better than a pound cake -- it's the right consistency -- and i would want the cc in the middle but -- and you can use any flavor combination you can come up with -- 

http://www.justapinch.com/recipes/dessert/cake/incredible-melted-ice-cream-cake.html

The cheesecake is for my granddaughters 21st birthday cake (the only reason I would consider) she wanted a three layer cake with the cheesecake on top so wasn't sure what to use for a recipe for the cheesecake if it would be just a normal cheesecake recipe

Ahh, I read layers and wrongly assumed you meant tiers.

Carry on.

i did the same thing too!

oh you can use any recipe -- baked or non-baked -- but you want a heavier cake underneath

you can baked a crustless cheesecake too -- freeze it for handling

You need to clarify whether you mean layers or tiers. This explains it: http://rosiescreativecakes.com/what-is-the-difference/

I think you mean three tiers with the top tier being cheesecake.

I'm not an expert at all but I think one problem would be the height of the cheesecake (if you do indeed mean tiers). It'd mean none of the tiers could be very tall. Also you'd need to serve the whole cake cold and regular cake doesn't taste as good cold. 

What about something like this: 

That way you could serve each cake at the proper temperature and you're not putting a heavy cheesecake on top of a delicate cake.

cevamel, she might could make a two layer cheesecake to get the better height -- I didn't spell it out very good but that's why I suggested a crustless one as well -- you can just stack 'em like regular layers glued together with ganache --

maybe you can use butter cream between layers and seal the deal with ganache so it doesn't budge -- can't remember if we used butter cream -- so long as temperature and moisture issues are controlled buttercteam would work -- oh yeah -- using a ganache dam, buttercteam filling will work -- a fruit filling would be wonderful