I don't think there is anything wrong with "good fit" here. As one of the definition of fit goes like this-:To be appropriate to; suit: music that fits your mood.But you could also use "apt" or "to the purpose" which sounds more formal.It should not be "are" a good fit,it should be "is" a good fit.
When regarded as a unit, collective nouns, as well as noun phrases denoting quantity, take singular verbs.( adopted from English language and usage site)
. . .
"Some of faculties research interests are diverse and interdisciplinary which is a good fit for my research interests." [Faculties research interests is taken as a unit.]