Simple Newbie Question about picking my domain name ?

[someguy]

I want to build a website/online store.

If all the .com names that I am wanting to use are already registered how bad would this hurt my name when it comes to SEO ?

Example:

marinestore.com

verses (Dropping the "e" off store)

marinestor.com

 

[elevator]

Someguy, you have to watch it carefully; using marinestor.com could be very dangerous for you should incase the owner of MarineStore.com has trademark on the name, you may pay him through your nose if taken to court
You can find another name such as marineshop.com, marinefoods.com if they are availble. It is not advisable to use that marinestor.com just seetddwn and think of something else. Good luck and cheers.