Making a marketplace in WP but not sure what to use

Hi I am wanting to make a multi vendor marketplace and as you can imagine since this has been done so many times I have allot of options on how to go about doing this.
The first way and probably the hardest/most time consuming would be for me to use my web design and front end development skills to create a marketplace that had no functionality, and then bring in a back end developer to give function to the site this way has many pros to it but it would be very difficult to make a fully functional marketplace for me since I don’t have the back end skills.

The second option would be to use a WordPress theme (and there are many) I will list the two I have in mind below:
My favourite: http://themeforest.net/item/squarecode-wordpress-theme/8219662
other one: http://themeforest.net/item/marketica-marketplace-wordpress-theme/8988002

now both of these have great design but the main things that are confusing me/dividing my opinion is first for the “SquareCode” theme this is my favourite and I love the design however this uses a paid plugin “Front End Submissions” easydigitaldownloads.com/extensions/frontend-submissions/?ref=4600
which I will happily buy but the other theme apparently uses a free plugin wordpress.org/plugins/wc-vendors/ so this has completely torn my opinion on which one to go for and or to go with my first idea of building a marketplace right from nothing which has its pros like a bespoke design and easily brand able but the WordPress idea is tempting since this will basically be a solo dev project.

Please give me any options or ideas you have on what I should to and it will be greatly appreciated, thanks Angus