I loved my old 165/60/14 CEAT tyres/standard wheels, nigh on indestructible and once you get the hang of them, handle pretty good. Never thumped a lump out of them and (ahem) I used to drive fast up some very rough roads.

Got a set of BBS 16in on the now and needing to replace tyres, seriously considering dropping the car another 20-40mm and sticking the 14's on as I can either get 2 tyres for the 16s for price of 4 14s... Stupid obscure sizes.
In response to you're question, I wouldn't see too much difference. Hypotheticaly you're accelleration would be improved at the expense of top end but it'd be so insignificant it's hardly worth bothering about.
What's the 14s look like?