Also I would like something that could double as a life raft.
Life rafts are not only terribly expensive and hopefully money thrown away but if the day comes that you REALLY need one, you will wish you found the money to get one. The only way a dinhgy will save you is if the boat is sinking in the Gulf due to equipment defect. It will not save you in bad weather!
But, until you can get a life-raft, not just an ordinary one, but an offshore one which of course cost much more

, it is smart to rig your dinhgy to substitue for one as you have no choice. What I used to do is deflate it when doing offshore passages and tie it to the stern handrails (only 12" off waterline) with a quick release knot. Of course I tested to see if it would float deflated as I put the pump inside the dinhgy and my plan was to pump it up while I floated in the water....like I said...no choice
But realiistically, sailing along the shore in the Gulf during the day, all you NEED is life jackets and flares (lots of them), a handheld radio, a mirror, a flashlight and an EPIRB.
Sad but true, you can get an EPIRB much cheaper than a life-raft or dinhgy and as long as you stay within 200 miles of shore, that is much better to have. As long as you are close to shore, you will be recued within an hour if you have those items with you. If you are outside of helicoper range, expect it to take days for a ship to be routed to you and that's when you absolutely have to have a life-raft.