Good answer 
You've put business before personal preference and that's important.
As you go through, start a checklist of things you want and need, but also make a list of things that you don't want or need.
My own list:
Wants
- Responsive
- Large, high quality inventory photos
- Fast loading homepage
- solid, functional inventory search, filtering and sorting
- fast and effective Service Booking
- custom inventory types
Don't Wants
- Video homepage
- iFrame solutions
- templated department pages
etc.
I'm a bit biased, but when I do consulting I try and help them identify these items, then I go back through the list and identify the rationale behind each item. Often times I find they are way further off mark than you are and they're making decisions based on what they, as an industry veteran, want from their website based on how they shop and browse.
I also recommend A/B testing and ensuring your vendor plays nice with other vendors - don't let your website vendor limit your selection of business vendors.
