How-to build a marketplace/exchange on Joomla? - Joomla! Forum - community, help and support

i'm in process of evaluating joomla! create *dedicated* marketplace or exchange users (end users, dealers, manufacturers) can come buy, sell, trade, , auction new , used equipment. in addition buying & selling, site act community discuss range of topics associated said equip, offer expert advice, tie in related news , events, , otherwise become "hub" clientele.

features:
* must support both desktop , mobile environments.
* look-n-feel: combination of art, news & music
* sellers: each seller manages own inventory. can upload 1 or more items. should simple , easy (i.e. drag-n-drop). each item can have description, price, pics, video, sound.
* buyer/seller ratings
* featured sellers & merchandise.
* buyers: simple & advance searching locating interested items; ability watch or monitor particular items; ability research pricing (i.e. kind of blue book capability)
* buyer/seller feedback
* multi-language support
* multi currency support
* multi payment support (paypal, google checkout, ...)

think ebay-ish dedicated specific clientele , set of products. think high brow spit & shine magazine. think "thee go place" reviews, recommendations, , feedback. think community.


question(s)

1) joomla 3.0, joomla 2.5?
2) template recommendations?
3) extension recommendations?
4) other?

i'm new joomla seasoned professional many years of experience building web applications large fortune 100 companies, technical issues not primary concern.

i don't have expertise in building retail sites 1 i've describe joomla and/or wordpress stacks, , looking advice on approach, gotchas, extension selection, etc.

i've investigate dozens of templates, extensions, , visited many many joomla sites, have relatively understanding of what's out there, i'm missing expert advice on best software stack purpose, for/what stay away from, hosting choices, etc.

in other words, sage advice experts in trenches.

thanks in advance feedback.

start picking nice theme, want responsive theme. check out yootheme, rocket theme, or themeforset responsive themes.

then need search extensions, sadly there no all-in-one solution , require lot of adjustments styling on extensions depending how made. i'd start finding template like.