Thoughts on visa. Depends on how much you're willing to spend.
Thoughts on condo. If you're willing to buy, have the money to buy. Don't mind that it works like a lease, which is obviously cheaper than monthly rental. Personally I don't mind since all the buildings in my country are 99 years shelf life and cost minimum 25 million baht for a studio. It's way cheaper for me here.
The only thing I would advice against. I did the 6 months in out. My condo unit was really dirty and dusty and black when I came back. Although I shut everything and even put in a door gap sealer thing you get on lazada. Even the toilet seat was black even though I closed it. Had to stay in the hotel 3 days till I engaged a condo cleaning service. Bought a new bed as well.
Well it depends what type of proposal you want. One with a view. Or one with those props, backdrops, flowers and balloons. Is it just propose and be done ? or is there something planned. Or you doing the one with the beach candlelight dinner? Or a nice hotel dinner?