your 92 distributor will fit if you modify it a little. You need to remove one of the legs on it. When you compare the two distributors it should be obvious what you need to change.
you can probably get some 19’s to fit. but personally i think it’ll be ugly.
silvia headlight conversion will be expensive. go to your local body shop and get a quote.
i would go with a new tach 'cause your redline should be higher and the stock tachs aren’t too accurate anyway, that is if you are going to be needed to pay attention to your tach. me, being the automatic type, let the computer do the shifting for me, but my husband, mr. shiftcrazy put the tach on his B16A swap .