yup a 1.7 would be a good choice as above have done a conversion witha friend in a ka and that was simple easier than my cvh into my ka!
the insurance wouldnt increase as much as it would witha cossie engine (as puma 1.7 is group 8 i think and cossie is towards group 20) in (plus to get that cossie in ya car ya lookingt at over 10k i reckon).
get a 1.7 head work, 4-2-1 manifold should see decent power!
good luck fella!
speak to pumabuild or pumaspeed for info