I would suggest to follow the Gentoo handbook first. Leave all options you are not sure as default, using lspci to find out more about your hardware specifications. >From my experiences I will make sure that the kernel is bootable first then adapt it to hardware later. Use modules or not is your choice, both ways work fine.
If you want to make sure that thing is stable, you can back up your old config later then have a bunch of test kernels to test. The help from kernel config interface does help you to get a general idea about what is the purpose of the option. Not everyone can get the kernel work for the first try, do not panic. Once you get through the first time, thing will go more smoothly than you thought. It happened to me one year before but now it take me about less than 10 minutes to have the new kernel configured in my computer. Good luck,
