i believe there are some good points here.... i am a chef at an italian restaurant and i do tend to think that in italian cuisine particularly, there arent many recipes which pair the both of them in a sauce - my inclination is that they could work somewhat well together as long as the sauce isn't too spicy... in regards to CAINE'S post, you are totally off my friend, i am with verablue and with every born-and-raised italian i have had the privilege of working with in a kitchen.... in the provinces of BASILICATA and CALABRIA in Southern Italy (not too far from the mentioned province of SICILY) the use of chilis in sauces is well-known... off the top of my head, the "Spaghetti All'Arrabiata" a classic and very well-known recipe comes to mind exclusively calls for the use of peperoncini since "arrabiata" means angry or fiery which is what the chilis seem to emit, a fieryness... and there is extensive use of these peperoncini on pizzas made in napoli (naples) where i find it pairs well with salted anchovies and black olives over a light coating of tomato passata.... the list goes on... when eating anywhere, people are already trusting the cooks decision in choosing the menu, the degree of saltiness, the consistency of a sauce, the degree of "al dente" in the pasta, so how would it be any different to trust the degree of spiciness?
and in other cuisines such as thai cuisine, as GB pointed out, that dish you mention is "pad kaprow" - in which the two main ingredients other than your meat are the fresh thai basil and the chilis.... i worked in a thai restaurant and they seemed to pair it excellently, however, in their cuisine they particularly look for a balance of salty-sour-sweet-spicy so there is also a hint of sugar which brings this dish more into balance than in an italian dish, so in the thai dish even though it is spicy as ****, the sweetness elevates the subtleties of the thai basil and allows it to come through beautifully!!!
cliveb, i later realized you were talking about a cream-based pasta sauce rather than tomato-based.... in this case, i think you could be better off going ahead and experimenting w the use of both since the dairy will tame the spiciness a bit and allow the basil to come through... i think as long as you keep the spiciness of the chilis to a minimum, you will have a great dish - perhaps not an italian one, but a good one nonetheless!!