Simon,
On deck stepped masts I prefer the plate as it keeps the load in the mast column, your not trying to pull your deck up. Further you are not drilling holes into the deck core, or at least not as many.
On Garhauer, I have used their products on three boats now and have been very pleased. About 2/3 $$ vs the other brands and quality & design is every bit as good. Call and talk with Guido; I have no connection to them, just very satisfied customer.
Another $$ saver for line is Cajun Trading, online out of Nova Scotia, nice quality cordage at about 2/3 of other sources plus no sales tax.