If you haven't got this taken care of, I can help. I'm a custom AV installer. I assume you've already figured out the power issues etc. So I'll skip that. Here's what I'd recommend regarding the TV.
First, there are a couple of manufacturers that make outdoor tvs. The most popular being SunBriteTV. The TVs are completely weatherproof. The smallest unit they make is a 32". Retail price on it is $3295. (doesn't include speakers) It's also considerably heavier than a standard 32" weighing in at 41bs. as opposed to an indoor 32" that might weight about 10 lbs.
How would I approach this if a customer asked? I'd tell them to take into account the law of diminishing returns. You can pay $3300 or you could pay $100 for the cheapest thing at Best Buy. Now, if your $100 TV gets ruined...you're not heartbroken and you're also not out $3300.
So, what's the downside to installing a $100 TV on your boat? A couple of things.
1. There's not a bigger picture killer than the sun. It has the ability to wash out a TV so it's not even visible. However, if you installed it under the bimini and pointed away from the sun, I can see getting a "passable" picture" that you'd probably be happy with.
2. Water- A $100 indoor TV isn't in any way designed to be outside. No way, No how. If it gets a drop of water on the back of it, it's done. Not to mention the risk of electrical shock by a wet person touching it.
However, if you can mange those things...It would work.
Now, how do you get picture? All HDTV's have an HD tuner built into them. So you buy a small HD antenna..something like this, plug it into the back of the tv, do a channel scan and you're off to the races!
https://www.bestbuy.com/site/mohu-l...v-antenna-black-white/3488006.p?skuId=3488006
Now, you're only getting your local channels.. Don't assume you'll be watching the Golf Channel out on your lake. If I can answer any questions, I'm happy to help.
Good luck!