With those wheels on the Novara Safari (if I'm thinking right) your options are somewhat limited for speed. The Conti Town & Country tires come in a narrower size if you like the tire. If you want something for 100% on-road use, go with Ritchey Tom Slicks in whatever width you please.
I liked my stock T&C's until flat number 5. Next spring I have set of 1.6" Conti Sport Contacts I'm going to mount. Light,smooth,higher pressure,puncture protection. I got them because of the many good reviews they've gotten here. I've also run 1.5" WTB Slickasauruses,which are fast but lack puncture protection,and Specialized Nimbus Flak Jackets in 1.5" which were decent all around but a touch heavy.
C'dale BBU('05 and '09)/F600/Super Six/Hooligan8and 3,Kona Dew Deluxe,Novara Buzz/Safari,Surly Big Dummy,Marin Pt Reyes/Novato,Giant Defy 1,Schwinn DBX SuperSport/Qualifier,Brompton S6L,Dahon Speed Pro TT
You'll lose some comfort almost gauranteed going from a wider low prssure tire to a narrower high pressure one. How narrow you want to go is up to you. Also, do you have snow/slush to contend with? Some widely spaced treading is nice for that.