Project Suitability

I’m looking having a multi vendor website built. i.e. Supplier lists items and buyer buys via a bid, just like a mini ebay but for specific products. So will require dashboards for seller, buyer and admin.

A few people I’ve asked want to build this in PHP using a framework, others have said ROR. I worked with PHP (Laravel) many years back and things have moved on a lot, but never in Ruby. Could you offer any advice on the two options at all ?
Is building a multi-vendor site easier due to the Gems in ROR? Any examples?
What I’m looking for is the ease of build, maintenance and extendibility.