I have a 20' SF with an aluminum bracket on it and its great. Good handling, gives me a ton more room in the boat, more top end. I went with aluminum because of cost, if I had unlimited funds for the SeaCraft would I of had HermCo make me a custom one with a platform and the works?..sure, but I don't and saved a couple thousand in the process.
I'm very happy with it.
As far as mounting, this
website helped me a lot.
Pic in action:
Not sure how much your engine weighs but my Zuke is 474# dry, I put a new transom in my boat last year and went back with Coosa to save on weight, moved batteries from the stern to under the console. Boat has the original thru-floor scuppers and original deck and is still self bailing with 2 people + gear.