OmegaOne is a great brand. If your local Petco/petsmarts are like mine, they don't carry New Life anymore, so it's harder to come by. Frozen foods are good, depending on which you get. Bloodworms are like candy for betta, and should only be given as a treat, not a meal. Daphnia are great, as are a few of the shrimp variety, including Brine. (I can't find Daphnia to save my life at any of my local stores).
I agree, a heater is a must. Do some research and find one that fits what you're plan is and what you want to spend. I know you said money isn't an issue, but at the same time I don't want to direct you to every top of the line, super expensive, item you could possibly get.
On filters, no matter what filter you get, if the current is too strong, you can always baffle it. The Tetra Whisper i series have really good flow, and if you happen to get one of the older models, you can actually adjust the flow - which is nice!
Along with plants (silk or real) I'd suggest a hide/cave for him to hide out in. Make sure it doesn't have any sharp edges or fake plants attached to it and that the holes are big enough for him to easily fit in. A lot of us use terracotta pots that you can get at either a home and garden store or a craft store (the later is usually cheapest).
Definitely use some water conditioners like either Prime or STressCoat+. Prime helps lock up ammonia and nitrites so it doesn't harm the fish in between water changes. I have both, and honestly can't tell a difference between my tanks I use them in. Both have aloe, which helps keep the fish's slime coat healthy, which in turn makes him less stressed and happier
Both will help with his fins, and you might want to do a salt bath for him to help make sure there isn't any infection on the fins, or his gills for that matter.
I'm glad that he found you and you're ready to make his life a bit brighter
He's lovely too!
