Macbook Pro Retina upgrade questions.

Hey guys,

A warm hello. This is my very first post on the community, and i feel privildged to be here. Been an iPhone user since gen 1, now want to extend my love to MacBook Pro Retina.

I am planning on getting the rMBP 15.5" 2.6Ghz, 16GB RAM, 256 Flash Storage. I am choosing the higher end setup in terms of CPU and RAM capacity, but below average in terms of storage. I already have 72TB media server hooked to my A/V Rack, that is on Windows Home Server. Most of the time i will be using the laptop at home, where i can map the network and store and access my files from the media server. But there might be times when i'll be touring, or on vacation. One of the main reasons i am getting the higher end laptop is for my new found love for Photography which requires CPU and memory intensive processing for rendering RAW images. I am not a pro, and wont be.. this is plain hobby.

Now here is my main question, will i be able to upgrade just the flash storage in the future. Not now!! Say like in a year or so? I realize there is a kit that can be used, but they dont have it for the newer models.. thats what my colleague told me.. is this true? And if so, how hard is to upgrade the storage on the newer mbp? i can setup new desktops etc.. so i somewhat good with PC hardware etc.

Also, if i install windows on the side, will running both the OS on the MBP draw double the cpu/memory resources? Its like when we install Windows in VMWare the cpu consumption doubles up along with RAM. Is this going to be the same for MBP?