Before wasting a lot of time and energy inquiring for web design quotes and negotiating prices, you will need to understand that even the best looking website can be very ugly in the eyes of search engine 'bots' like Google, Bing & Yahoo.
If the website is not built by a company that puts the efforts in SEO (Search Engine Optimisation) above a fancy website design and advanced web development features, then you are most likely going to be another website out there in the dark with 2 "natural" clicks per month.
When websites are not ranking on page 1, or even in the top 5 in Google for some industry relevant, competitive and high volume keyphrase, then only expensive pay-per-click campaigns or other secular "offline advertising" such as print, tv or radio will get respectable quantities of website visitors to your homepage.
Therefore, you shouldn't put off learning "What is SEO" for later. If you are thinking: "Lets get the website done first and think about SEO later", then think again.