most people call sheet vinyl,lino.they are however two differant products.the main mgf.'s armstrong,mannington tarkett & congoleum only sell sheet vinyl,if you want lino it is mgf.in europe and japan, lino is very expensive,but it is very good and worth the $40,00 to $50.00 it sells for,if you are looking for a great kitchen floor the best product on the market today is ultima from congoleum (home depot sells it @ $19.99/sy)
to remove the existing sheet vinyl from your floor the best way is to cut out the sheet viny and the underlayment with it(both at the same time) then install new underlayment.
you may be able to install over your existing sheet vinyl if it is only one layer.
your best bet is to have a pro give you a bid before you do anything,...good luck

Most professionals just put a 1/4 inch underlayment over existing vinyl. The reason for this is the possibility of asbestos being in older sheet goods. Covering it is no problem but if it does have asbestos and you remove it, disposing of it could be a problem $$$ and a health hazard as well.

Franklyn
http://WoodFloorist.com