Don't confuse the programming process with the design process. In general most good programmers can not design well and most good designers can not program well. I have never designed a web page for a client before, I always work with their designer (sometimes in house and sometimes contracted) and do my best to make their design functional. When I finish I tell them to test it and the designer gives me a list of changes that they want made to keep with their stylistic vision. If the firm you are with is doing well on the technical end have them keep going, perhaps they need a designer to create the pages and they can make them work.
Edit: On that note I'm posting this comic



This look and feel thing is a common problem that clients get. There is no way anyone can design off of your exact feelings so you will never get the exact product you have in your head (if it even exists, often times your dream idea is just that).

The first question you need to ask is what do you stand to lose by continuing as you are now. Is it going to hurt your revenue? If so by how much? If you feel you will make a profit by spending more on an experienced designer than it is a good idea to go forward with that.

What you are describing is an interface designer, they have experience in how to make a site smooth and easy to use while keeping it good looking. Here are salary stats for these jobs in the US (I don't know what they go for in Switzerland but the median income is a lot higher for you so it may be more):
http://swz.salary.com/SalaryWizard/I...y-Details.aspx
http://swz.salary.com/SalaryWizard/I...y-Details.aspx

Keep in mind that consultants will charge considerably more than the hourly rate you will derive from that because contractors incur more expenses.