i've heard excellent recordings made with less.
so i'd say the answer is yes.
you might consider adding a better preamp for your vocals.
the GT Brick or an RNP would do the job. the RNP might give you more bang for buck though as its a 2 channel pre.
also i'm an ex-RNC owner and a current RNLA owner. its a little more gooey, great for the extra few bucks. i'll probably get a 2nd RNLA soon.
just my $0.02
good luck!